研究者紹介システム

佐俣 博章
サマタ ヒロアキ
大学院海事科学研究科 海事科学専攻
教授
工学その他
Last Updated :2022/09/16

研究者情報

所属

  • 【主配置】

    大学院海事科学研究科 海事科学専攻
  • 【配置】

    海洋政策科学部 海洋政策科学科, 海事科学部 マリンエンジニアリング学科

学位

  • 博士(工学), 青山学院大学

授業科目

ミニ講義

ジャンル

  • 科学・技術 / 物理学

コメントテーマ

  • 電気電子材料学
  • 電子物性工学
  • 結晶合成
  • 超伝導材料
  • 永久磁石材料

研究活動

研究キーワード

  • 結晶構造解析
  • 熱電変換材料
  • 金属間化合物
  • 酸化物
  • 無機化合物
  • 結晶合成

研究分野

  • ナノテク・材料 / 無機材料、物性
  • ものづくり技術(機械・電気電子・化学工学) / 電気電子材料工学
  • 自然科学一般 / 磁性、超伝導、強相関系

論文

  • Wavelength conversion characteristics of Y1-x-yErxYbyBaZn3AlO7

    Masashi Hanioka, Yusuke Furukawa, 佐俣 博章

    2019年02月, Optik, 180, 1043 - 1048, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Masashi Hanioka, Seigo Arimoto, 佐俣 博章

    Co-doped gadolinium oxides, Gd1.98−xYbxEr0.02O3 were synthesized by a flux method, and their up- and down-conversion characteristics were investigated. For 980 nm excitation, green and red up-conversion emissions were observed. The color coordinates on the Commission Internationale de I'Eclairage chromaticity diagram shifted along a straight line from green to red with an increase in the Yb3+ content x. For 365 nm excitation, the intensity of the down-conversion emission decreased with an increase in x, owing to the quenching of the excitation energy of Er3+ by the Yb3+ ions. The up- or down-conversion emissions are observed up to 100 °C. For Gd1.98−xYbxEr0.02O3, x = 0.04 was appropriate for the bidirectional wavelength conversion.

    Elsevier GmbH, 2018年02月01日, Optik, 154, 226 - 233, 英語

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    研究論文(学術雑誌)

  • Yuichi Furuyama, Ryoma Nakamori, Sho Nagai, Akira Taniike, Hiroaki Samata, Akira Kitamura

    In order to investigate the CO2 absorption characteristics of the low- and high-density Li2TiO3 samples, X-ray diffraction (XRD) and non-Rutherford backscattering spectroscopy (NRBS) analyses have been performed. Crystallographic structure of a sintered sample is decided by the XRD analysis, and the NRBS analysis has evaluated the amount of CO2 absorption quantitatively. The amount of CO2 absorption of the low-density Li2TiO3 samples is increased with increase of the humidity. We find that the humidity has effect on CO2 absorption to the low-density Li2TiO3 samples. On the other hand, the high-density samples sintered at temperatures higher than 1,470 K absorb very little CO2 under high humidity conditions.

    Elsevier Ltd, 2016年12月01日, Nuclear Materials and Energy, 9, 227 - 232, 英語

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    研究論文(学術雑誌)

  • Hiroaki Samata, Masashi Hanioka, Tadashi C. Ozawa

    Samarium oxyhydroxide (SmOOH) crystals were synthesized using a flux method. The as-grown crystals were yellowish, transparent, and elongated with a maximum length of approximately 1.0 mm. SmOOH adopts a monoclinic structure in the space group P2(1)/m with a=0.4356 nm, b=0.3766 nm, c=0.6139 nm, and beta=108.464 degrees. The magnetic susceptibility of the SmOOH crystals exhibited typical Van Vleck paramagnetism, and the experimental data at temperatures above 200 K were in close agreement with the calculated results using a spin-orbit coupling constant lambda=443 K (308 cm(-1)), (C) 2015 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2016年01月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 398, 82 - 85, 英語

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    研究論文(学術雑誌)

  • Hiroaki Samata, Katsutoshi Kobayashi, Masashi Hanioka, Tadashi C. Ozawa

    Gd0.9-xRxEu0.1OOH (R=Y, La) crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a monoclinic structure belonging to the P2(1)/m space group. The unit cell volumes of the Gd0.9-xLaxEu0.1OOH crystals increased with increasing x, whereas those of Gd0.9-xYxEu0.1OOH decreased with increasing x. The Commission Internationale de I'Eclairage (CIE) chromaticity coordinates of Gd0.9-xRxEu0.1OOH (R=Y, La) crystals were located in the red region and were nearly constant over the range of x values considered. The fluorescence quantum yield Phi(f) monotonically decreased with increasing x regardless of the ionic radii of the substitute ions. The fact that the Phi(f) value of La0.9Eu0.1OOH was greater than that of Gd0.9Eu0.1OOH indicated that the observed decrease in the Phi(f) values of the Gd0.9-xLaxEu0.1OOH crystals up to x=0.3 could not be attributed to an increase in the distance between Eu3+ ions or to a decrease in the Gd3+ content. The decrease might be due to an increase of killer centers introduced by elemental substitutions with the larger ion.

    ELSEVIER SCIENCE BV, 2015年12月, Journal of Rare Earths, 33 (12), 1256 - 1260, 英語

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    研究論文(学術雑誌)

  • Hiroaki Samata, Shungo Imanaka, Masashi Hanioka, Tadashi C. Ozawa

    Crystals of co-doped gadolinium oxyhydroxide (GdOOH), Gd0.98Eu0.02-xTbxOOH and Gd1-y-zDyyBizOOH, were synthesized by a flux method. The color coordinates in the Commission Internationale de I'Eclairage (CIE) chromaticity diagram of Gd0.98Eu0.02-xTbxOOH, obtained under 254 nm irradiation, shifted along a straight line with the changing values of x to include the yellow region. The CIE coordinates of Dy3+ doped in GdOOH were located in the yellow region, while the emission intensity of Dy3+ under 286 nm irradiation increased by more than 40 times when co-doped with Bi3+.

    ELSEVIER SCIENCE BV, 2015年07月, JOURNAL OF RARE EARTHS, 33 (7), 712 - 716, 英語

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    研究論文(学術雑誌)

  • Hiroaki Samata, Naoki Wada, Tadashi C. Ozawa

    Europium oxyhydroxide crystals were synthesized by the flux method. The as-grown crystals were transparent and had a plate-like shape with natural flat surfaces. The powder XRD data were refined by assuming a monoclinic structure of the space group P2(1)/m and lattice parameters of a=0.4346 nm, b=0.3744 nm, c=0.6107 nm, and beta= 108.62 degrees. The magnetic susceptibility of the EuOOH crystals exhibited typical Van Vleck temperature-independent paramagnetism below 120 K. The calculated susceptibility, based on Van Vleck's theory, agreed with the experimental data to some extent, with the coupling constant lambda=458 +/- 10 K. The experimental results were in close agreement with the results calculated using a modified formula with lambda=505 +/- 2 K and a constant term C=4.6x10(-4) emu/(mol.Oe).

    ELSEVIER SCIENCE BV, 2015年02月, JOURNAL OF RARE EARTHS, 33 (2), 177 - 181, 英語

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    研究論文(学術雑誌)

  • Yuichi Furuyama, Kyohei Yahata, Ryoma Nakamori, Akira Taniike, Hiroaki Samata, Akira Kitamura

    Non-Rutherford backscattering spectroscopy (NRBS) for the composition analysis and X-ray diffraction (XRD) for the crystallographic structure analysis have been applied to the blanket candidate material, Li2TiO3, which is known to absorb CO2 though chemically stable. It is found that the amount of CO2 absorbed by atmospheric exposure of the low- and medium-density samples is greater than or comparable to that by dry CO2 gas exposure. By varying the density of the Li2TiO3 and composition of the ambient gas, conditions to minimize the amount of CO2 absorbed are discussed. (C) 2014 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2014年12月, JOURNAL OF NUCLEAR MATERIALS, 455 (1-3), 527 - 530, 英語

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    研究論文(学術雑誌)

  • Hiroaki Samata, Daisuke Itakura, Shungo Imanaka, Tadashi C. Ozawa

    Scientific Research Publishing, 2014年03月, Journal of Materials Science and Chemical Engineering, 2 (3), 23 - 29, 英語

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    研究論文(学術雑誌)

  • T. Ohnishi, S. Mizusaki, M. Naito, Y. Nagata, M. Itou, Y. Sakurai, T. C. Ozawa, Y. Noro, H. Samata

    The crystallographic, magnetic and transport properties of Sr1-x Ca (x) Ru0.5Mn0.5O3 were studied to reveal the effects of crystal symmetry on the magnetism and the transport properties of antiferromagnetic SrRu1-y Mn (y) O-3 (y > 0.2). The Ca-content dependences of the lattice constants and volume suggest that the mixed valence state of Mn3+, Mn4+, Ru4+, and Ru5+ ions in SrRu0.5Mn0.5O3 is held for Ca substitution. However, a structural transformation from tetragonal to orthorhombic symmetry occurs at a Ca content of x similar to 0.2, and a ferromagnetic state appears simultaneously. The Weiss temperature of all samples has a positive value regardless of the magnetic state. The resistivity decreases as the Ca content increases, and the high temperature part of the resistivity could be fitted by using the variable range hopping (VRH) model. The localization length increases as soon as ferromagnetism appears. The Curie temperature seems to depend on the distance between transition metal ions. The antiferromagnetic state was explained by using the competition between a ferromagnetic interaction along the c-axis and an antiferromagnetic interaction in the ab-plane, and the orthorhombic ferromagnetic state was explained by using a three-dimensional ferromagnetic interaction between Mn ions.

    KOREAN PHYSICAL SOC, 2013年07月, Journal of the Korean Physical Society, 62 (12), 1887 - 1892, 英語

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    研究論文(学術雑誌)

  • The role of 3d electrons in the appearance of ferromagnetism in the antiferromagnetic Ru2MnGe Heusler compound: a magnetic Compton scattering study

    S Mizusaki, T Ohnishi, A Douzono, M Hirose, Y Nagata, M Itou, Y Sakurai, T C Ozawa, H Samata, Y Noro

    2012年05月, Journal of Physics: Condensed Matter, 24 (25), 255601(7pp), 英語

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    研究論文(学術雑誌)

  • Synthesis and Characterization of CaPd3O4 Crystals

    Hiroaki Samata, Satoshi Tanaka, Soichiro Mizusaki, Yujiro Nagata, Tadashi C. Ozawa, Akira Sato, Kosuke Kosuda

    2012年01月, Journal of Crystallization Process and Technology, 2 (1), 16 - 20, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, A. Douzono, T. Ohnishi, T. C. Ozawa, H. Samata, Y. Noro, Y. Nagata

    The present study reveals that the correlation between the magnetic properties with composition x in the polycrystalline Ru2Mn(1-x)Fe(x)Ge system. Hard ferromagnetic properties appeared at the intermediate composition between antiferromagnetic Ru2MnGe with soft ferromagnetic Ru2FeGe. Ru2Mn0.6Fe0.4Ge shows an anisotropic and negative magnetoresistance (MR) effect more than 8% although the both end materials are small MR effect less than 1%. These experimental results correlate the variation in MR ratio with that of coercive field as a function of x. Moreover, the correlation is shown at the boundary of magnetism between antiferromagnetic and ferromagnetic. Therefore, the present experimental results imply that the coexistence of antiferromagnetic and soft ferromagnetic leads to induce the MR effect in this system. (C) 2011 Published by Elsevier B. V.

    ELSEVIER SCIENCE SA, 2012年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 510 (1), 141 - 146, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, T. Ohnishi, T. C. Ozawa, Y. Noro, H. Samata, M. Itou, Y. Sakurai, Y. Nagata

    The magnetic properties of the polycrystalline Heusler compound Co2TiAl were investigated by the classical experimental methods and the magnetic Compton scattering experiment. The X-ray diffraction profile at room temperature can be identified as the phase of the L2(1)-type ordered structure. The magnetic field and temperature dependence of magnetization show that Co2TiAl has the typical soft ferromagnetic properties with T-C of 120 K and the saturation magnetization of 0.70 mu(B) per formula unit. The resistivity shows a typical metallic behavior at temperatures up to 300 K. The magnetoresistance (MR) effect with the MR ratio of -8% appears in the vicinity of T-C. The characteristics of the magnetic Compton profile are similar to that of the well-known ferromagnetic metals such as Ni and Fe. The experimental results indicate that the origin of the MR effect observed for Co2TiAl is similar to that for conventional ferromagnetic materials.

    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2011年10月, IEEE TRANSACTIONS ON MAGNETICS, 47 (10), 2444 - 2446, 英語

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    研究論文(学術雑誌)

  • T. Ohnishi, Y. Takahashi, S. Mizusaki, H. Samata, Y. Noro, Y. Nagata

    The crystallographic and magnetic properties of LnXBe (Ln = lanthanides; X = Si or Ge) were investigated. All the samples have a hexagonal structure of space group P63/mmc. LnSiBe (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Er) and LnGeBe (Ln = Pr, Nd, Sm, Gd, Tb, Dy, Ho) are ferromagnetic (T-c of 6-70 K), whereas LnSiBe (Ln Dy, Ho) are antiferromagnetic and LnSiBe (Ln = La, Lu) and LnGeBe (Ln = La, Eu, Er, Lu) are paramagnetic. Possible existence of superconductivity was observed for paramagnetic LaSiBe. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559470]

    AMER INST PHYSICS, 2011年04月, JOURNAL OF APPLIED PHYSICS, 109 (7), 07E327(1 - 3), 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, N. Kawamura, T. Taniguchi, Y. Nagata, T. C. Ozawa, A. Sato, Y. Noro, H. Samata

    The single crystal of the new ternary compound Sm12Fe14Al5 was grown and its crystallographic and magnetic properties were investigated. Sm12Fe14Al5 has a hexagonal structure of the space group p-3m1 and shows ferromagnetism with a Curie temperature of 245 K. The easy direction of magnetization is parallel to the c-axis at temperatures between 245 and 85 K; however, it changes to the c-plane below 85 K through a first-order-like phase transition. No saturation is observed in the magnetization curve even under the applied field of 55 kOe at 5 K. Sm12Fe14Al5 seems to have a large coercive field at very low temperatures. The anisotropy field was estimated at 5 and 120 K and the saturation magnetization of low temperature phase is explained assuming a ferromagnetic coupling between Fe and Sm sublattices. (C) 2009 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2010年07月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 322 (13), L19 - L24, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, M. Naito, T. Taniguchi, Y. Nagata, M. Itou, Y. Sakurai, Y. Noro, T. C. Ozawa, H. Samata

    The variation of the magnetic moment on Ru and Mn atoms in the Ca0.3Sr0.7Ru1-xMnxO3 system was investigated by the magnetic Compton scattering technique using synchrotron radiation. The Ca0.3Sr0.7Ru1-xMnxO3 system has ferrimagnetism with an antiferromagnetic coupling between Ru and Mn, and the dominant magnetic component changes from ferromagnetic Ru to ferromagnetic Mn at x similar to 0.25 as the Mn substitution proceeds. The mechanism for the change in the magnetism of Ca0.3Sr0.7Ru1-xMnxO3 is discussed.

    IOP PUBLISHING LTD, 2010年04月, JOURNAL OF PHYSICS-CONDENSED MATTER, 22 (14), 145601(8pp), 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, A. Douzono, T. Ohnishi, Y. Nagata, T. C. Ozawa, H. Samata, Y. Noro

    The crystallographic and magnetic properties of the quaternary Heusler alloys Ru2Mn1-xVxGe were investigated. Although the end members, Ru2MnGe (x = 0) and Ru2VGe (x = 1), are antiferromagnetic and paramagnetic, ferromagnetism with Curie temperature over 200 K appeared at about x = 0.3. The saturation magnetization had a maximum (1.6 mu(B)/f.u.) at x = 0.5. The ferromagnetism was explained by a model which assumes a preferential site occupation of V atoms and a collapsing of the next nearest-neighbor antiferromagnetic Mn-Mn interactions by V.

    IOP PUBLISHING LTD, 2010年, INTERNATIONAL CONFERENCE ON MAGNETISM (ICM 2009), 200, 052017, 英語

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    研究論文(国際会議プロシーディングス)

  • S. Mizusaki, T. Ohnishi, Y. Kozaki, Y. Nagata, M. Itou, Y. Sakurai, Y. Noro, H. Samata

    Magnetism of SmFe7 was studied by magnetic Compton scattering experiment with the synchrotron radiation along with those of SmFex (x = 2, 3) and Sm6Fe23. Spin moment and orbital moment for SmFe7 were 6.60, and 7.20 mu(B)/f.u., respectively. The magnetic Compton profile revealed that the spin moment of SmFe7 compounds consists of negative Sm moment and positive Fe moment. The comparison to other Sm-Fe crystals shows that the spin, orbital, and total moments increase linearly against a Fe/Sm ratio.

    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2009年10月, IEEE TRANSACTIONS ON MAGNETICS, 45 (10), 4399 - 4401, 英語

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    研究論文(学術雑誌)

  • S. Taniguchi, M. Ogawara, N. Fukuoka, S. Mizusaki, Y. Nagata, Y. Noro, H. Samata

    Epitaxial thin films of CaRu(1-x)M(x)O3 (M = Ti, Mn) were fabricated on a (001)-SrTiO3 substrate by spin-coat method using organometallic solutions (metal alkoxides). Results of X-ray diffraction and transmission electron microscopy indicate that the epitaxial films were grown pseudomorphically so as to align the [001] axis of the CaRu1-xMxO3 films perpendicular to the (001) plane of the SrTiO3 substrate. Ferromagnetism and metal-insulator transition are induced by the substitution of transition metal ions. The occurrence of ferromagnetism was explained qualitatively assuming a TiRu6 cluster model for CaRu1-xTixO3 film and a mixed valence model for CaRu1-xMnxO3 film. Ferromagnetism was also observed for layered CaRuO3/CaMnO3 film and CaRuO3/CaMnO3/CaRuO3/CaMnO3 multilayer film and the magnetism was explained by an interfacial exchange interaction model with magnetic Mn3+, Mn4+, and Ru5+ ions. (C) 2009 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2009年10月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 321 (19), 3335 - 3341, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, T. Taniguchi, N. Okada, Y. Nagata, N. Hiraoka, M. Itou, Y. Sakurai, Y. Noro, T. C. Ozawa, H. Samata

    The magnetism of CaRu1-xMnxO3( 0.2 <= x <= 0.9) was studied by the magnetic Compton scattering experiment. The result of the spin-polarized electron momentum density distributions (magnetic Compton profiles) and the absolute value of spin moment indicate that Mn doping introduces magnetic moments on Ru ions, and the Ru and Mn spin moments were antiferromagnetically coupled. Moreover the spin moment of Ru ions increased proportionally in the x range. These results were explained by a mixed valence model and inhomogeneous magnetic structure, where the inhomogeneous magnetic ground state in CaRu1-xMnxO3 would be formed by a ferrimagnetic network from the Mn3.5+ and Ru4.5+ clusters in the paramagnetic matrix CaRuO3 for x < 0.5 and in the antiferromagnetic matrix CaMnO3 for x > 0.5.

    IOP PUBLISHING LTD, 2009年07月, JOURNAL OF PHYSICS-CONDENSED MATTER, 21 (27), 276003(6pp), 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, Y. Toyoda, K. Nakayama, Y. Nagata, T. C. Ozawa, Y. Noro, H. Samata

    The performance of phosphate glasses as a catalyst for water decomposition and a proton conductor was investigated. Glasses with a composition of 30Na(2)O-10BaO-30P(2)O(5)-(30-x)WO(3)-xNb(2)O(5) (5 < x < 25) decompose water vapor and generate hydrogen at 500 degrees C. The best decomposition performance was observed on a specimen with the Nb(2)O(5) composition of x = 15. A part of hydrogen produced on the glass surface changes to protons by reducing W(6+) ions and penetrates into the glass. The electron is the dominant charge carrier in the electric conduction of W-rich glasses, whereas proton conduction is predominant in Nb-rich glasses in hydrogen atmosphere. A Raman scattering experiment revealed that Nb contributes to depolymerize the -P-O-P- chains in the phosphate glass producing non-bridging oxygen. A possible model was proposed for the water decomposition and proton conduction processes. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2009年06月, JOURNAL OF NON-CRYSTALLINE SOLIDS, 355 (16-17), 960 - 964, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, T. Ohnishi, A. Douzono, Y. Nagata, T. C. Ozawa, H. Samata, Y. Noro

    Anomalous magnetic behavior was found in the polycrystalline Heusler alloy system Ru2 Mn1-x Fex Ge. Samples of x=0 and 1.0 show no magnetoresistance (MR) however, the anisotropic MR effect is observed for x=0.5 (MR ratios of -4% and +2% are observed under parallel and perpendicular configurations of applied field and applied current, respectively). Moreover, magnetic measurement revealed that the sample of x=0 is antiferromagnetic, whereas the samples of x=0.5 and 1.0 are ferromagnetic with Curie temperatures of 270 and 490 K, respectively. The saturation magnetization and coercivity at 5 K are 3.1 μB /f.u. and negligibly small for x=1.0 and 1.8 μB /f.u. and 0.1 T for x=0.5, respectively. The MR effect is explained by a model in which antiferromagnetic and ferromagnetic domains coexist. © 2009 American Institute of Physics.

    2009年, Journal of Applied Physics, 105 (7), 07E513(1 - 3), 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, Y. Adachi, T. Ohnishi, T. Taniguchi, Y. Nagata, T. C. Ozawa, Y. Noro, H. Samata

    Crystals of ternary LnRu(2)P(2) (Ln = Pr, Nd, Sm, Tb, Dy, Er) systems were synthesized, and their crystallographic, magnetic, and electric properties were investigated. All the crystals have a tetragonal ThCr2Si2-type structure of space group) 14/mmm. The lattice constants decrease as the number of 4f electrons increases, reflecting the lanthanide contraction. An antiferromagnetic transition was observed for LnRu(2)P(2), (Ln=Pr, Nd. Sm. Tb, Dy) at 25 K (Pr) 19 K (Nd) 15 K (Sin) 22.5 K (Tb), and 13 K (Dy). However, no transition was observed for ErRu2P2 down to 5 K. The P-eff agrees well with the theoretical moment g root J(J+1) of lanthanide's, suggesting that lanthanides make a major. or contribution to the magmetic moment of LnRu(2)P(2). A spin-flop-like transition was observed in the M(H) curves of PrRu2P2 and TbRu2P2, at 4 and 8 kOe. respectively; however. no saturation was observed Lip to 55 kOe. (c) 2008 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2009年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 468 (1-2), 28 - 33, 英語

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    研究論文(学術雑誌)

  • H. Samata, D. Kimura, S. Mizusaki, Y. Nagata, T. C. Ozawa, A. Sato

    Single crystals of neodymium oxyhydroxide NdOOH were grown using an electrochemical method. Crystals having a maximum size of about 2 mm in length were grown. The structure was identified by single crystal X-ray diffraction and the refinement converged to R1 = 0.0170 and wR1 = 0.0426. NdOOH crystallizes in a monoclinic structure of the space group P2(1)/m with lattice parameters of a = 4.3896(2) angstrom, b = 3.83 19(2) angstrom, c = 6.2424(3) angstrom, and beta = 108.131(2)degrees, and Z = 2. The resistivity shows semiconductor-like characteristics with the activation energy E-a = 0.93 eV. No magnetic order was found down to 5 K. (C) 2008 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2009年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 468 (1-2), 566 - 570, 英語

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    研究論文(学術雑誌)

  • H. Samata, Y. Saeki, S. Mizusaki, Y. Nagata, T. C. Ozawa, A. Sato

    Single crystals of CaRu1-xMnxO3 and SrRuO3 were grown using an electrochemical technique with calcium or strontium chloride as a solvent, and the crystallographic properties of grown crystals were characterized by single-crystal X-ray diffraction and powder X-ray diffraction. CaRu1-xMnxO3 and SrRuO3 crystals with natural surfaces were obtained on the cathode, reflecting the characteristic of the growth in a liquid phase. In spite of the low synthesis temperature of 780 C, the size of CaRuO3 crystals was relatively large (similar to 2.5 mm in length). The Mn content of grown crystals was in proportion to the molar ratio of Mn2O3/RuO2 at the synthesis, and CaRu1-xMnxO3 crystals with different compositions could be obtained by only changing the ratio of the raw materials. (C) 2008 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2009年01月, JOURNAL OF CRYSTAL GROWTH, 311 (3), 623 - 626, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, J. Sato, T. Taniguchi, Y. Nagata, S. H. Lai, M. D. Lan, T. C. Ozawa, Y. Noro, H. Samata

    The crystallographic, magnetic, and electric properties of CaMn1-xIrxO3 (0 <= x <= 0.6) were investigated. The lattice constants increase with increasing content of Ir. Specimens of 0.05 <= x <= 0.2 show antiferromagnetic behavior; however, ferromagnetism is observed for specimens of 0.3 <= x <= 0.6. T-N decreases as the Ir content increases. T-N is superseded by T-C without passing 0 K and TC continues to increase in the ferromagnetic composition range. The effective moment mu(eff) decreases as the Ir content increases. The Weiss temperature is negative for small x; however, it continues to increase while changing its sign at about x = 0.3. The results were explained by assuming a mixed valence state of Mn3+, Mn4+, Ir4+, and Ir5+ ions. The composition dependence of mu(eff) could be explained qualitatively using the ion fractions estimated from the Ir content dependence of the unit cell volume. Experimental results suggest the coexistence of antiferromagnetic and ferromagnetic phases. When the volume fraction of the ferromagnetic phase dominates that of the antiferromagnetic phase, the system seems to show ferromagnetism.

    IOP PUBLISHING LTD, 2008年06月, JOURNAL OF PHYSICS-CONDENSED MATTER, 20 (23), 235242(7pp), 英語

    [査読有り]

    研究論文(学術雑誌)

  • S. Mizusaki, T. Taniguchi, N. Okada, Y. Nagata, M. Itou, Y. Sakurai, T.C. Ozawa, Y. Noro, H. Samata

    The magnetism of CaRu(1-x)Mn(x)O(3) was studied using magnetic Compton scattering measurements for polycrystalline specimens at 10 K under 2.5 T using a synchrotron-radiation x ray. The spin moment deduced from the magnetic Compton profiles has a maximum at x=0.7 and the value agrees with the result of the magnetization measurement. The magnetic Compton profiles indicate that the Mn spin moment is dominant in magnetization and that Ru moment, which is induced with Mn doping, couples with Mn spin moment antiferromagnetically. The results suggest that a sort of ferrimagnetism is established in the CaRu(1-x)Mn(x)O(3) system.

    AMER INST PHYSICS, 2008年04月, Journal of Applied Physics, 103 (7), 英語

    [査読有り]

    研究論文(学術雑誌)

  • S. Mizusaki, T. Taniguchi, N. Okada, Y. Nagata, M. Itou, Y. Sakurai, T. C. Ozawa, Y. Noro, H. Samata

    The magnetism of CaRu(1-x)Mn(x)O(3) was studied using magnetic Compton scattering measurements for polycrystalline specimens at 10 K under 2.5 T using a synchrotron-radiation x ray. The spin moment deduced from the magnetic Compton profiles has a maximum at x=0.7 and the value agrees with the result of the magnetization measurement. The magnetic Compton profiles indicate that the Mn spin moment is dominant in magnetization and that Ru moment, which is induced with Mn doping, couples with Mn spin moment antiferromagnetically. The results suggest that a sort of ferrimagnetism is established in the CaRu(1-x)Mn(x)O(3) system.

    AMER INST PHYSICS, 2008年04月, JOURNAL OF APPLIED PHYSICS, 103 (7), 07C910(3pp), 英語

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    研究論文(学術雑誌)

  • M. Naito, S. Mizusaki, T. Taniguchi, Y. Nagata, T. C. Ozawa, Y. Noro, H. Samata

    Crystallographic, magnetic, and electrical properties of Ca1-ySryRu1-xMnxO3 were investigated. The lattice parameters decrease with increasing Mn content without following Vegard's law. Ferromagnetism with the Curie temperature T-C higher than 200 K occurs when the Ru site is replaced by Mn (x>0.3), and the T-C and the magnetization have a maximum at x=0.6-0.7. The occurrence of the ferromagnetism was explained assuming mixed valence states of Mn3+, Mn4+, Ru4+, and Ru5+ ions. Furthermore, T-C increased when the Ca site is replaced by Sr. The enhancement of T-C seems to be due to a change in the crystal symmetry caused by the Sr substitution. The maximum T-C=275 K was marked for specimen of Ca0.5Sr0.5Ru0.4Mn0.6O3. (C) 2008 American Institute of Physics.

    AMER INST PHYSICS, 2008年04月, JOURNAL OF APPLIED PHYSICS, 103 (7), 07C906(3pp), 英語

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    研究論文(学術雑誌)

  • T. C. Ozawa, A. Matsushita, Y. Hidaka, T. Taniguchi, S. Mizusaki, Y. Nagata, Y. Noro, H. Samata

    Synthesis and characterization of Sr(1-x)A(x)Pd(3)O(4)(A = Na, Bi) are reported. All the doped phases crystallize in the cubic symmetry with the space group Pm3m. Both Hall and thermopower measurement results indicate that substitutions of Na+ and Bi3+ into the Sr2+ site introduce hole and electron carriers, respectively. As the dopant concentration increases, effective magnetic moment, electrical conductivity and carrier concentration of these phases increase and thermopower decreases. The highest power factor obtained among these doped samples is 0.5 mu W/K-2 cm at room temperature for Sr0.8Na0.2Pd3O4 (c) 2007 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2008年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 448 (1-2), 77 - 83, 英語

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    研究論文(学術雑誌)

  • T. C. Ozawa, T. Taniguchi, Y. Kawaji, S. Mizusaki, Y. Nagata, Y. Noro, H. Samata, H. Mitamura, S. Takayanagi

    Ln(2)BaPdO(5) (Ln = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho) all crystallizes in NdBaZnO5 structure which is proposed to have a Shastry-Sutherland (S-S) lattice of Ln 31 ions. Ln(2)BaPdO(5) (Ln = Nd, Sm, Gd, Dy, He) exhibits antiferromagnetic transitions at temperatures between 2 and 5 K. In addition, metamagnetic transitions have been observed for Ln(2)BaPdO(5) (Ln = Nd, Dy, Ho) below 2 K. Specific heat of Ln,BaPdO5 (Ln = Ho, Dy) exhibits symmetric peaks at T-N, and residual entropy below TN is negligibly small. On the contrary, specific heat of Ln(2)BaPdO(5) (Ln = Nd, Sm, Gd) exhibits Schottky type anomalies followed by sharp peaks at TN, and residual entropy below TN is large. From these results, the applicability of the S-S model to Ln(2)BaPdO(5) with various Ln(3+) ions is proposed. (c) 2007 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2008年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 448 (1-2), 96 - 103, 英語

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    研究論文(学術雑誌)

  • T. C. Ozawa, A. Ikoshi, T. Taniguchi, S. Mizusaki, Y. Nagata, Y. Noro, H. Samata, S. Takayanagi

    Magnetic properties of a series of orthorhombic NaLnTiO(4) (Ln = Sm, Eu, Gd, Tb, Dy, Ho and Er) characterized by heat capacity measurements are reported. Magnetic transitions are observed for all NaLnTiO(4) investigated except for Ln = Eu. The change in magnetic entropy closely agrees with the expected theoretical values except for Ln = Sm and Gd. Peak profiles in temperature dependence of heat capacity indicate that Ln = Sm, Tb, Dy, Ho and Er phases possess Ising square lattices. Furthermore, Ln = Gd also exhibits the similar property regardless of its S state; there seems some degree of anisotropy in its magnetic lattice. Magnetization and heat capacity data indicate that superexchange through oxygen is the dominant spin interaction in this system. (c) 2007 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2008年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 448 (1-2), 64 - 68, 英語

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    研究論文(学術雑誌)

  • T. C. Ozawa, A. Ikoshi, T. Taniguchi, S. Mizusaki, Y. Nagata, Y. Noro, H. Samata

    A series orthorhombic NaLnTiO(4) (Ln=lanthanides) has been synthesized and characterized. These compounds all crystallize in A-site ordered n=1 Ruddlesden-Popper phase (A(n+1)B(n)O(3n+1)) Structure. The weak ferromagnetism with large magnetization has been observed for Ln = Tb and Dy, and non-linear field dependence of magnetization without hysteresis has been observed for Ln = Er and Ho. By performing the symmetry operations, two possible canted spin arrangements have been proposed. (c) 2006 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2008年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 448 (1-2), 38 - 43, 英語

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    研究論文(学術雑誌)

  • T. Taniguchi, S. Mizusaki, N. Okada, Y. Nagata, S. H. Lai, M. D. Lan, N. Hiraoka, M. Itou, Y. Sakurai, T. C. Ozawa, Y. Noro, H. Samata

    The crystallographic and magnetic properties of CaRu(1-x)Mn(x)O(3) (0 <= x <= 1.0) were investigated in detail by x-ray powder diffraction, magnetization, and magnetic Compton scattering measurements. The lattice parameters show considerable deviation from Vegard's law. Ferromagnetism appears at a relatively large Mn concentration (x >= 0.2), and the magnetization and the Curie temperature have a maximum at a Mn content near x=0.7. The magnetic Compton scattering measurement revealed that Mn makes a dominant contribution to the magnetization and the Mn moment is antiparallel to the Ru moment, which is induced by Mn doping. The anomalous change in the unit cell volume and the occurrence of ferromagnetism were discussed on the basis of the mixed-valence model of Mn(3+), Mn(4+), Ru(4+), and Ru(5+) ions. The Mn-composition dependence of the spontaneous magnetization was explained semiquantitatively assuming (1) ferromagnetic coupling between Mn(3+) and Mn(4+) ions, (2) antiferromagnetic coupling between Ru(5+) and Mn ions, and (3) the theoretical spin moments of Mn(3+), Mn(4+), and Ru(5+). The ferromagnetic interaction between Mn(3+) and Mn(4+) ions seems to make a dominant contribution to the Curie temperature. The CaRu(1-x)Mn(x)O(3) system is considered to be a ferrimagnet induced through competition between the ferromagnetic interaction between Mn ions and the antiferromagnetic interaction between Ru(5+) and Mn ions.

    AMER PHYSICAL SOC, 2008年01月, PHYSICAL REVIEW B, 77 (1), 014406(7pp), 英語

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    研究論文(学術雑誌)

  • H. Samata, D. Kimura, Y. Saeki, Y. Nagata, T. C. Ozawa

    Single crystals of lanthanum oxyhydroxide (LaOOH) were grown using an electrochemical method. Crystals having a maximum size of 7.0 mm in length, 1.5 mm in width, and 0.7 mm in thickness were grown. LaOOH crystallizes in a monoclinic structure of the space group P2(1)/m with a lattice parameter of a = 0.4417 nm, b = 0.3926 nm, c = 0.6573 nm, and beta = 112.32 degrees. LaOOH crystals completely changed to lanthanum trihydroxide La(OH)(3) within 48 h in ambient atmosphere by water absorption. Maintenance at 390 degrees C by heat treatment was effective to maintain the structure of LaOOH for at least a week. (c) 2007 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2007年06月, JOURNAL OF CRYSTAL GROWTH, 304 (2), 448 - 451, 英語

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    研究論文(学術雑誌)

  • T. Taniguchi, S. Mizusaki, N. Fukuoka, Y. Nagata, Y. Noro, H. Samata

    Epitaxial thin films of CaRu1-xMxO3 (M = Mn, Fe) were fabricated on a (0 0 1)-SrTiO3 substrate by a spin-coating method using organometallic solutions (metal alkoxides). The results of X-ray diffraction and transmission electron microscopy (TEM) indicate that the epitaxial films were grown pseudomorphically in order to align the [0 0 1] axis of the CaRu1-xMxO3 films perpendicularly to the (0 0 1) plane of the SrTi03 substrate. Ferromagnetism and metal-insulator transition are induced by the substitution of transition metals. The results can be explained qualitatively by assuming a charge transfer of Mn4+ + Ru4+ -> Mn3+ + Mn4+ + Ru4+ + Ru5+. (c) 2006 Published by Elsevier B.V.

    ELSEVIER SCIENCE BV, 2007年03月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310 (2), 1067 - 1069, 英語

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    研究論文(学術雑誌)

  • S. Mizusaki, N. Kawamura, T. Taniguchi, M. Itou, H. Samata, Y. Noro, Y. Sakurai, Y. Nagata

    The spin-polarized electron momentum distributions (magnetic Compton profiles: MCP's) of SmFe1.86Al0.14 along the [111] direction have been measured at 10 and 300 K using the magnetic Compton scattering technique. It is found that the orbital moment dominates the magnetization in this compound. A comparison with a theoretical profile support that the shape of the experimental MCP's is reproduced by a sum of positive Fe and negative Sm 4f spin components. A slight difference is observed in the shape of MCP between 10 and 300 K. (c) 2006 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2007年03月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310 (2), 1635 - 1636, 英語

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    研究論文(学術雑誌)

  • T. Taniguchi, S. Mizusaki, N. Okada, Y. Nagata, K. Mori, T. Wuernisha, T. Kamiyama, N. Hiraoka, M. Itou, Y. Sakurai, T. C. Ozawa, Y. Noro, H. Samata

    Neutron powder diffraction and magnetic Compton scattering measurements were conducted for ferromagnetic CaRu0.85Fe0.15O3 at temperatures between 10 and 300 K. Anomalous volume expansion was observed in the neutron diffraction measurement below the Curie temperature (85 K), and Invar-like behavior was observed below 40 K. However, no structural phase transition was observed down to 10 K. The strong correlation between the volume expansion, Delta V, and the square magnetization, M-2, suggests that the anomalous volume expansion is due to the magnetovolume effect that is caused by the occurrence of ferromagnetism. The magnetic Compton scattering experiments revealed the existence of a magnetic moment on Ru and the antiferromagnetic configuration of Fe and Ru moments. The formation of a ferrimagnetic order through the induction of the magnetic moment on the Ru ion is a possible reason for the anomalous volume expansion observed for CaRu0.85Fe0.15O3.

    AMERICAN PHYSICAL SOC, 2007年01月, PHYSICAL REVIEW B, 75 (2), 024414(6pp), 英語

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    研究論文(学術雑誌)

  • N Kawamura, T Taniguchi, S Mizusaki, Y Nagata, TC Ozawa, H Samata

    Magnetism of intermetallic compounds SmFe2, SmFe3, Sm6Fe23, and SmFe7 were studied in detail using single crystals and the use of these materials has been discussed. SmFe2 and Sm6Fe23 have cubic magnetocrystalline anisotropy and the easy axis of magnetization in the [111] direction. SmFe2 has giant negative magnetostriction that can be used for microactuator or ultrasonic generator. SmFe3 has a relatively large saturation moment and uniaxial anisotropy, which are promising for application as a perpendicular magnetic recording medium. Large saturation magnetization and extremely large magnetocrystalline anisotropy of SmFe7 seem promising as an absorber in the frequency range of milliwave as well as a high performance permanent magnet. (c) 2005 Elsevier Ltd. All rights reserved.

    NATL INST MATERIALS SCIENCE, 2006年01月, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, 7 (1), 46 - 51, 英語

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    研究論文(学術雑誌)

  • K Nakayama, MJ Nishi, T Taniguchi, S Mizusaki, Y Nagata, TC Ozawa, Y Noro, H Samata

    Phosphate glasses dissociating hydrogen from water vapor were prepared and their performance was evaluated. Glasses with compositions of 30Na(2)O-10BaO-30P(2)O(5)-(30-x)Nb(2)O5-xWO(3) (5 < x < 25) dissociated water vapor into hydrogen and oxygen around 500 degrees C. The best dissociation performance was observed on a specimen with the tungsten composition of x=15. The result suggests that the coexistence of Nb2O5 and WO3 is important in obtaining a high performance of hydrogen dissociation. When Nb2O5 was replaced by other transition metal oxides such as MoO3, the amount of hydrogen dissociation decreased by one-third. (c) 2005 Elsevier Ltd. All rights reserved.

    NATL INST MATERIALS SCIENCE, 2006年01月, SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, 7 (1), 52 - 55, 英語

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    研究論文(学術雑誌)

  • T Taniguchi, N Fukuoka, TC Ozawa, Y Nagata, Y Noro, H Samata

    Epitaxial thin films of ABO(3) (A =Ca, Sr; B = 3d, 4d transition metal) were fabricated on a (100)-SrTiO3 substrate by spin coating an organic metal and subjecting it to successive heat treatments. Results of X-ray diffraction and transmission electron microscopy indicate that the growth is pseudomorphic and the [001] axis of the ABO(3) film is perpendicular to the (100) plane of the SrTiO3 substrate and that its pseudocubic axes align parallel to the cubic axes of the SrTiO3 crystal. Epitaxial ABO(3) thin films have similar transport and magnetic properties to those of bulk materials.

    IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005年10月, IEEE TRANSACTIONS ON MAGNETICS, 41 (10), 3355 - 3357, 英語

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    研究論文(学術雑誌)

  • S Yamada, N Fukuoka, T Taniguchi, TC Ozawa, Y Nagata, T Uchida, H Samata

    An epitaxial CaRuO3 thin film was fabricated on the (100)-SrTiO3 substrate by spin-coating an organic metal and subjecting it to successive heat treatments. Results of X-ray diffraction, reflection high-energy electron diffraction, and transmission electron microscopy indicate that the growth is pseudomorphic and the [001] axis of the CaRuO3 film is perpendicular to the (100) plane of the SrTiO3 substrate and its pseudocubic axes align parallel to those of the SrTiO3 crystal. The epitaxial CaRuO3 thin film has a similar transport property to that of bulk CaRuO3 crystal. (c) 2004 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2005年05月, THIN SOLID FILMS, 478 (1-2), 1 - 5, 英語

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    研究論文(学術雑誌)

  • TC Ozawa, T Taniguchi, Y Kawaji, Y Nagata, Y Noro, H Samata, S Takayanagi

    Antiferromagnetic ordering and spin frustration behaviors in the series of isostructural compounds, R2BaPdO5 (R = rare earth), are reported. We have investigated the crystallographic, magnetic and thermal properties of the compounds, R2BaPdO5 (R = Nd, Eu, Gd and Ho). R2BaPdO5 (R = Nd, Gd and Ho) show paramagnetic properties at high temperatures originating only from the rare-earth ions and magnetic order at 2.1, 2.9 and 4.1 K, respectively. Ho2BaPdO5 shows a symmetrical peak of the heat capacity at T-N and negligible residual entropy below the T-N, suggesting a simple square lattice Ising model. On the contrary, Nd2BaPdO5 and Gd2BaPdO5 show Schottky type heat capacity at TN and large residual entropy far below the T-N, suggesting spin frustration in them. The origin of the possible spin frustration in R2BaPdO5 (R = Nd and Gd) is discussed in terms of relative strength of J and J' in the Shastry-Sutherland spin lattice. (c) 2005 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2005年03月, PHYSICS LETTERS A, 337 (1-2), 130 - 134, 英語

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    研究論文(学術雑誌)

  • T Taniguchi, Y Kawaji, TC Ozawa, Y Nagata, Y Noro, H Samata, MD Lan

    The crystallographic and magnetic properties of R2BaPdO5 (R = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho) were investigated. R2BaPdO5 has a tetragonal lattice (P4/mbm) and rare-earth ions make a layered structure with the R-O-R chain. where major R-O-R magnetic interaction occurs. R2BaPdO5 (R = La, Eu) showed a paramagnetic behavior with small temperature-dependent susceptibilities, indicating the non-magnetic states of Pd2+. The effective moment P-eff of R2BaPdO5 (R = Pr, Nd, Gd, Dy, Ho) can be explained by g(1)rootJ(J + 1) of the rare-earth ions. R2BaPdO5 (R = Nd, Sm, Gd, Dy, Ho) showed antiferrornagnetism with T-N between 2 and 5 K. R2BaPdO5 (R = Dy, Ho) showed metamagnetic transition at 2 K, whereas a clear metamagnetic transition was not observed for R2BaPdO5 (R = Gd, Nd). No magnetic transition was observed for Pr2BaPdO5 in spite of the Curie-Weiss-type paramagnetic behavior at higher temperatures. The saturation magnetization estimated at 2 K from the magnetization at 70 kOe was explained by taking account of Kramer's doublet for R2BaPdO5 (R = Nd, Sm, Dy) and the enhancement by the exchange interaction for Ho2BaPdO5. (C) 2004 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2005年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 386 (1-2), 63 - 69, 英語

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    研究論文(学術雑誌)

  • 透明有機EL素子に用いる陰極の検討

    内田 孝幸, 三村 寿文, 金田 真吾, 星 作太郎, 佐俣 博章, 永田 勇二郎, 大塚 正男

    2004年06月, 電気学会論文誌C, 124 (6), 1244 - 1250, 日本語

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    研究論文(学術雑誌)

  • A Koriyama, M Ishizaki, TC Ozawa, T Taniguchi, Y Nagata, H Samata, Y Kobayashi, Y Noro

    The magnetic properties of CaRuO3 were studied using polycrystalline and single-crystal samples. The M(T) curves of the polycrystalline sample showed irreversible behavior, and the M(H) curve showed weak ferromagnetic behavior below 60 K. No irreversible behavior was observed in the M(T) curves of a pseudo-cubic crystal sample at temperatures between 1.7 and 300 K. It was concluded that the irreversible behavior observed for the polycrystalline sample is not an intrinsic property of CaRuO3. The M(H) curve of the crystal sample showed peculiar behavior at 1.7 and 5 K, suggesting the existence of magnetic order at very low temperature. The Mossbauer study for the (CaRu0.99Fe0.01O3)-Fe-57 crystal revealed that no magnetic order exists at temperatures down to 15 K; however, a sextet was observed at 2 and 5 K, suggesting the existence of magnetic order. Therefore, it was concluded from the results of magnetization and the Mossbauer measurements that no magnetic order exists at temperatures down to 15 K; however, possible magnetic order occurs in CaRuO3 at a temperature below 15 K. (C) 2003 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2004年06月, JOURNAL OF ALLOYS AND COMPOUNDS, 372 (1-2), 58 - 64, 英語

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    研究論文(学術雑誌)

  • T Taniguchi, Y Nagata, TC Ozawa, M Sato, Y Noro, T Uchida, H Samata

    The electric and magnetic properties of Sr1-xNaxPd3O4 (0 less than or equal to x less than or equal to 0.2) were studied using polycrystalline specimens. The electrical conductivity increases following the substitution of Na, and an insulator-metal transition was observed for very small Na contents between 0.075 and 0.1. The results of Hall-effect measurements indicate that holes are introduced depending on the Na contents. Paramagnetic behavior with an increase of the susceptibility at low temperature was observed for all specimens. No abrupt shrinking of the lattice was observed near the insulator-metal transition. The insulator-metal transition seems to arise not in the form of a Mott transition but by a process in which Na-substitution directly introduces mobile carriers into the valence band, establishing a metallic state for specimens with x > 0.75. This must be due to the semimetallic character of the electronic band structure of SrPd3O4. (C) 2003 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2004年06月, JOURNAL OF ALLOYS AND COMPOUNDS, 373 (1-2), 67 - 72, 英語

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    研究論文(学術雑誌)

  • M Kasahi, S Abe, T Taniguchi, T Ozawa, Y Nagata, H Samata

    New superconducting intermetallic compounds with a chemical formula of MRhGe2 (M = Zr, Hf) were discovered, and their crystallographic, magnetic, and electric properties were investigated. MRhGe2 crystallizes in an orthorhombic TiMnSi2 structure of space group Pbam and shows a superconducting transition at about 3 K. The magnetic susceptibility measurement indicated bulk superconductivity of MRhGe2. The superconducting parameters of MRhGe2 (M = Zr, Hf) indicate that they are type-II superconductors in the category of the BCS theory. (C) 2003 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2004年04月, JOURNAL OF ALLOYS AND COMPOUNDS, 368 (1-2), 51 - 57, 英語

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    研究論文(学術雑誌)

  • Synthesis and properties of Ba3NaRu2O9-(delta) and Ba-3(Na, R)Ru2O9-delta (R=rare earth) crystals

    H Samata, M Kai, T Uchida, M Ohtsuka, G Tanaka, S Sawada, T Taniguchi, Y Nagata

    Crystals of Ba3NaRu2O9-delta (deltaapproximate to0.5) and Ba-3(Na, R)Ru2O9-delta (R=Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm and Yb) were grown by an electrochemical method, and their crystallographic, magnetic, and electric properties were studied. All crystals have a hexagonal structure of space group P6(3)mmc. Ba3NaRu2O9-delta and Ba-3(Na, R)Ru2O9-delta (except Ce) have a negative asymptotic Curie temperature suggesting the existence of an antiferromagnetic order; however, they are paramagnetic at temperatures above 1.7 K. Ba3NaRu2O9-delta has an effective magnetic moment P-eff of 0.91 mu(B), while P-eff of Ba-3(Na, R)Ru2O9-delta (except Ce) reflects the large free-ion moment grootJ(J+ 1) of the rare earth ions. Ba-3(Na, Ce)Ru2O9-delta shows peculiar magnetic behavior that differs from the magnetism of other Ba-3(Na, R)Ru2O9-delta crystals. The resistivity of all crystals exhibits an activation-type temperature dependence with an activation energy in the range of 0.1similar to0.2 eV. (C) 2002 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2003年02月, JOURNAL OF ALLOYS AND COMPOUNDS, 350 (1-2), 77 - 85, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of RRhO3 (R=rare earth)

    T Taniguchi, W Iizuka, Y Nagata, T Uchida, H Samata

    RRhO3 (R=rare earth except Ce and Pm) was prepared by a solid-state reaction, and its crystallographic, magnetic, and electric properties were investigated. RRhO3 has an orthorhombic perovskite-type structure of the space group Pbnm. RRhO3 shows Curie-Weiss paramagnetism above 5 K. On the other hand, EuRhO3 shows antiferromagnetic behavior. The Rh3+ ion, which seems to be in the low-spin state, has a very small effective magnetic moment (P-eff=0.295 mu(B)/ion). The P-eff value of the RRhO3 compounds shows the same dependence on the number of 4f electrons as the gJ value of the rare-earth ions. The rare-earth ions make a major contribution to the magnetic moment of RRhO3. The resistivity of all RRhO3 shows an activation-type (or semiconductor-like) temperature dependence. (C) 2002 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2003年02月, JOURNAL OF ALLOYS AND COMPOUNDS, 350 (1-2), 24 - 29, 英語

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    研究論文(学術雑誌)

  • H Samata, R Kasai, T Taniguchi, Y Nagata

    Sm(Fe1-xAlx)(2), Sm(Fe1-xAlx)(3), Sm-6(Fe1-xAlx)(23), and Sm(Fe1-xAlx)(7) crystals were grown by a modified self-flux method, and their magnetic properties were investigated. The saturation magnetization of all compounds decreases by Al substitution. With the Al substitution, the anisotropy field decreases in the Sm(Fe1-xAlx)(3) and Sm(Fe1-xAlx)(7) systems, while in cubic Sm(Fe1-xAlx)(2) and Sm-6(Fe1-xAlx)(23) systems it increases considerably. The Curie temperatures of the compounds are dependent on the average distance between the nearest neighbor Fe atoms. (C) 2003 Elsevier Science (USA). All rights reserved.

    ACADEMIC PRESS INC ELSEVIER SCIENCE, 2003年02月, JOURNAL OF SOLID STATE CHEMISTRY, 171 (1-2), 339 - 344, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of Sr2Pd1-xMxO3 (M=Co, Cu)

    Y Nagata, T Taniguchi, G Tanaka, M Satho, H Samata

    The crystallographic and magnetic properties of Sr-2(Pd1-xMx)O-3 (M=Co, Cu) were studied. Sr-2(Pd1-xCox)O-3 (xless than or equal to0.25) and Sr-2(Pd1-xCux)O-3 (0less than or equal toxless than or equal to1) have an orthorhombic structure in the space group Immm. All specimens of both systems have a negative asymptotic Curie temperature. However, they show paramagnetic behavior at temperatures above 1.7 K. The effective magnetic moment P-eff increases with an increasing content of Co and tends to be saturated above x=0.25. However, in the case of Cu, P-eff shows a maximum at about x=0.2. The magnetic moment of Pd seems to become enhanced by the Cu substitution. Even though Sr2PdO3 is an insulator, its resistivity decreases with Cu substitution, and Sr2CUO3 shows semiconductor-like behavior. (C) 2002 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2002年11月, JOURNAL OF ALLOYS AND COMPOUNDS, 346 (1-2), 50 - 56, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of Mn1-xMxBe2 (M = Co, Ni, Cu) and MnBe2-xMx (M = Cu, B, Al)

    H Samata, S Abe, T Taniguchi, Y Nagata

    The occurrence of ferromagnetism was investigated in the Laves-phase compounds Mn1-xMxBe2 (M=Co, Ni, Cu) and MnBe2-xMx (M=Cu, B, Al) through magnetization measurements. The magnetic susceptibility is enhanced when Mn is replaced by Co and shows a maximum at about x=0.6. Ferromagnetic behavior is observed for specimens with a Co content of 0.3<x<0.9. However, the magnetization does not saturate in high magnetic fields and shows a linear field dependence up to 100 kOe, suggesting the existence of weak ferromagnetism. The results of measurements for the specimens Mn1-xMxBe2 (M = Co, Ni, Cu) have suggested that the number of valence electrons of the transition-metal atoms is important for the occurrence of the weak ferromagnetism. (C) 2002 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2002年09月, JOURNAL OF ALLOYS AND COMPOUNDS, 343 (1-2), 47 - 52, 英語

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    研究論文(学術雑誌)

  • Y Nagata, T Shioga, T Taniguchi, T Uchida, L Zhang, MD Lan, H Samata

    The magnetism and superconductivity of Sm1.85-xGdxCe0.15CuO4-delta and Gd2-yCeyCuO4-delta crystals were investigated. In the Sm1.85-xGdxCe0.15CuO4-delta system, superconductivity is suppressed by Gd substitution, and temperature-induced magnetic transitions appear at 3, 7, and 135 K above x=1.2 Cu spins have an antiferromagnetic (AF) order along the [110] direction among these transitions, and a weak-ferromagnetic (WF) moment due to a canting of Cu spins appears along the [(1) over bar 10] direction at Tless than or equal to3 K and 7 Kless than or equal toTless than or equal to135 K. The AF order at 3 Kless than or equal toTless than or equal to7 K changes into a canted spin configuration via field-induced spin reorientation and induces the WF moment. The Neel temperature T-NCu (135 K at x=1.2) and spin-reorientation temperature T-SR (7 K at x=1.2), which are due to the Cu sublattice and are observed at low field intensity, increase with increasing x. Sm spins have an antiferromagnetic order along the [001] direction at x=0 below the Neel temperature T-NR (similar to5 K), but T-NR, which is observed for low x at high field intensity, decreases with increasing x and disappears at xapproximate to1. Gd spins have an antiferromagnetic order along the [(1) over bar 10] direction for specimens with x>1.4 near 3 K. The change in the geometry of rare-earth and Cu spins resulting from Gd substitution is considered to be the reason for the suppression of superconductivity.

    AMERICAN PHYSICAL SOC, 2002年03月, PHYSICAL REVIEW B, 65 (10), 104506(12pp), 英語

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    研究論文(学術雑誌)

  • Y. Nagata, T. Shioga, T. Taniguchi, T. Uchida, L. Zhang, M. D. Lan, H. Samata

    The magnetism and superconductivity of (formula presented) below the Néel temperature (formula presented) which is observed for low x at high field intensity, decreases with increasing x and disappears at (formula presented) Gd spins have an antiferromagnetic order along the (formula presented) direction for specimens with (formula presented) near 3 K. The change in the geometry of rare-earth and Cu spins resulting from Gd substitution is considered to be the reason for the suppression of superconductivity. © 2002 The American Physical Society.

    2002年, Physical Review B - Condensed Matter and Materials Physics, 65 (10), 1 - 12, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of RFe1-xMnxO3 (R = Pr, Gd, Dy)

    Y Nagata, S Yashiro, T Mitsuhashi, A Koriyama, Y Kawashima, H Samata

    A novel magnetic transition was observed in a perovskite-type oxide of PrFe1-xMnxO3 (R=Pr, Gd, Dy; 0 <x <0.6). When iron ions in weak-ferromagnetic RFeO3 are replaced by manganese ions, the Curie temperature T-C decreases monotonically as the Mn content increases, and a spin-reorientation transition from antiferromagnetism to weak-ferromagnetism appears at low temperature. The transition temperature T-R depends on the Mn content and increases with increasing x, coinciding with the T-C at a Mn content near x = 0.5. The spin-reorientation transition seems to be caused by a change in the superexchange interaction and magnetocrystalline anisotropy introduced by the substitution of Mn. The effect of Mn-substitution on the electric resistivity was also studied and compared with that of Ca-substitution in the Pr1-xCaxFeO3 system. Ca-substitution has a remarkable effect on the resistivity but Mn-substitution causes a slight change in it. (C) 2001 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2001年12月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 237 (3), 250 - 260, 英語

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    研究論文(学術雑誌)

  • Crystal growth of rare earth-iron intermetallic compounds by the flux-creep-up method

    H Samata, K Sakamoto, S Yashiro, Y Nagata

    A new flux method for the crystal growth of rare earth-iron intermetallic compounds was developed. In this method, the rare-earth flux creeps up the inner surface of a BN-coated crucible during the cooling process, and free-standing crystals are left on the bottom of the crucible. This method was applied to the crystal growth of compounds in Sm-Fe and Nd-Fe systems, and crystals of SmFe2, SmFe3, Sm6Fe23, and Nd6Fe13-xAl1+x, were grown for the first time. In particular, SmFe7 is a new phase in the Sm-Fe system with high performance as a permanent magnet. Since the chemical composition of the mixture in the crucible changes in accordance with the creep-up of the flux, this method may be promising in the search for new phases as well as for the crystal growth of known materials. (C) 2001 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2001年07月, JOURNAL OF CRYSTAL GROWTH, 229 (1), 482 - 486, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of Sm6Fe23 crystal

    H Samata, T Uchida, Y Shimizu, S Sato, SM Yashiro, Y Nagata

    A single crystal of Sm6Fe23 was prepared by means of a modified self-flux method, and its crystallographic magnetic properties were studied. Sm6Fe23 has the cubic Th6Mn23-type structure (space group Fm3m) with a lattice constant of a = 1.2187 +/-0.0006 nm. The easy axis of magnetization is parallel to the < 111 > direction. Its magnetic moment per unit formula deduced from the saturation magnetization is 59 mu (B) at 5 K, a value that is consistent with the value calculated assuming ferromagnetic coupling between the Sm and Fe sublattices. The cubic anisotropy constants K, and K, estimated from the magnetization curves of the [111], [110], and [100] directions are -2.7 x 10(6) and 6.3x10(5) erg/cm(3), respectively, The anisotropy field H-A calculated from the anisotropy constants is 6.1 kOe. (C) 2001 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE SA, 2001年06月, JOURNAL OF ALLOYS AND COMPOUNDS, 322 (1-2), 37 - 41, 英語

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    研究論文(学術雑誌)

  • Superconductivity of the new intermetallic compound TaPtSi

    S Yashiro, R Kasai, A Kasahi, Y Nagata, H Samata, T Uchida, MD Lan

    A new superconducting intermetallic compound with a chemical formula of TaPtSi was discovered in the Ta-Pt-Si system, and its crystallographic, magnetic, and electric properties were investigated. TaPtSi crystallizes in an orthorhombic structure (space group Pnma) with the lattice constants of a = 0.6388 nm, b = 0.3808 nm,and c = 0.7353 nm. A superconducting transition was observed at 3.54 and 3.43 K, respectively, in the electrical resistivity and magnetic susceptibility measurements. The magnetic susceptibility measurement indicated that the superconducting volume fraction was about 100%, suggesting the bulk superconductivity of TaPtSi, Superconducting parameters indicate that TaPtSi is a compound in the category of type-II superconductors. (C) 2000 Elsevier Science Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 2000年10月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 61 (10), 1591 - 1596, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of Sm(Fe1-xAlx)(7) crystals

    H Samata, M Kamonji, H Sasaki, S Yashiro, M Kai, T Uchida, Y Nagata

    Sm(Fe1-xAlx)(7) (x=0, 0.047, 0.07 and 0.12) crystals were grown by the self-flux method, and their crystallographic and magnetic properties were investigated. Sm(Fe1-xAlx)(7) crystallizes in a tetragonal structure of the space group P4(2)/mnm, and aluminum occupies the iron site. The structure is very similar to that of Nd2Fe14B except that the boron sites are vacant. The Curie temperature, T-C, increases with a modest Al substitution in spite of little changes in the saturation magnetization M-s. However, both T-C and M-s decrease for a higher Al substitution. All the specimens have negative K-1 and positive K-2. The easy axis of magnetization is parallel to the [100] direction since K-1 + 2K(2) < 0 is satisfied for all the specimens. Although the magnitude of K-1 + 2K(2) decreases and becomes closer to zero with increasing Al content, aluminum substitution seems to be ineffective to change the easy direction from the basal plane to the c-axis. (C) 2000 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 2000年10月, JOURNAL OF ALLOYS AND COMPOUNDS, 311 (2), 130 - 136, 英語

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    研究論文(学術雑誌)

  • New Equiatomic Silicides of MM’Si (M=Nb, Ta;M’=Pt, Rh) and Superconductivity of Ta1-xNbxPtSi

    S. Yashiro, A. Kasahi, R. Kasai, H. Samata, Y. Nagata

    The present study focuses on the crystallographic, electric, and magnetic properties of the new intermetallic compounds of NbPtSi and MRhSi (M=Nb, Ta) and the substitution effect on the superconductivity of TaPtSi in the system of Ta1-xNbxPtSi (0 less than or equal to x less than or equal to 1). The crystal structure of NbPtSi and MRhSi was refined assuming an orthorhombic Co,Si structure of the space group Pnma. MRhSi (M=Nb, Ta) has metallic conductivity and shows diamagnetic behavior at temperatures between 1.7 and 350 K. On the other hand, NbPtSi shows paramagnetic behavior with metallic conduction. In the Ta1-xNbxPtSi system, the superconductivity of TaPtSi (T-c=3.5 K) is suppressed by Nb substitution. The Nb-content dependence of the Pauli-paramagnetic susceptibility suggests that reduction of the density of states at the Fermi-level is a possible reason for the suppression of superconductivity. (C) 2000 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 2000年09月, Journal of Alloys and Compounds, 309 (1-2), 51 - 56, 英語

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    研究論文(学術雑誌)

  • New optical technique for bulk magnetostriction measurement

    H Samata, Y Nagata, T Uchida, S Abe

    A new optical technique was applied to the measurement of magnetostriction in bulk samples. This technique utilizes an optical fiber bundle, AC-modulated light and lock-in detection. Deformation of the sample is determined from the ratio of the incident and reflected light intensities. Noise due to the instability of the light source is eliminated by obtaining the ratio of the incident and reflected light intensities, and the noise caused in the detector circuit can be reduced by lock-in detection. The performance of this method was characterized with a series of measurements using a gold film and crystal disks of pure iron and nickel. This technique offers a resolution of 0.5 nm and is sensitive enough to measure magnetostriction as small as 5 x 10(-7) in 1 mm thick samples. (C) 2000 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2000年04月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 212 (3), 355 - 360, 英語

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    研究論文(学術雑誌)

  • Magnetic properties of the Laves-phase compounds Fe1-xCoxBe2

    H Samata, Y Nagata, S Morita, G Tanaka, T Mitsuhashi, S Yashiro, S Abe

    The magnetic properties of polycrystalline and single-crystalline Fe1-xCoxBe2 were investigated by magnetization, Mossbauer, and torque measurements. Curie temperature (880 K at x = 0) and magnetic moment (1.94 mu(B) at 5 K for a specimen with x = 0) decrease with increasing content of Co. The Go-content dependence of the magnetic moment could be explained by considering magnetic moments of Co. Co seems to have a magnetic moment induced by an interaction between Co and the nearest neighbor iron atoms. Hexagonal anisotropy constants were determined as K-u1 = 9.7 X 10(5) erg/cm(3) and K-u2 = 9.9 X 10(4) erg/cm(3) for a specimen with x = 0 and K-u1 = 3.4 X 10(5) erg/cm(3) and K-u2 = 3.3 X 10(4) erg/cm(3) for x = 0.1. Co substitution is ineffective to the improvement of the magnetic anisotropy of FeBe2. (C) 2000 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 2000年04月, JOURNAL OF ALLOYS AND COMPOUNDS, 302 (1-2), 29 - 35, 英語

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    研究論文(学術雑誌)

  • Magnetism and transport properties of HfMSi (M = PT, Pd) and HfRh1-xPdxSi

    S Yashiro, Y Nagata, H Samata, S Abe

    The crystallographic, electric, and magnetic properties of the new intermetallic compounds HfMSi (M = Pt or Pd) and the superconductivity of HfRh1-xPdxSi were studied. The crystal structure of HfPtSi and HfPdSi could be refined assuming an orthorhombic structure (space group Pnma) and lattice constants of a = 0.6549 nm, b = 0.3883 nm, and c = 0.7505 nm for HfPtSi and a = 0.6570 nm, b = 0.3874 nm, and c = 0.7565 nm for HfPdSi. Both compounds are metallic and show diamagnetic behavior below 300 K. A small effective electron mass is thought to be a reason for the diamagnetism of HfMSi (M = Pt or Pd). In the HfRh1-xPdxSi system, the superconductivity of HfRhSi (T-c = 2.2 K) is suppressed by replacing Ph by Pd. The Pd content dependence of the Pauli paramagnetic susceptibility suggests that reduction of the density of states at the Fermi level is a possible cause of the suppression of superconductivity in the HfRh1-xPdxSi system. (C) 2000 Published by Elsevier Science S.A. AU rights reserved.

    ELSEVIER SCIENCE SA, 2000年02月, JOURNAL OF ALLOYS AND COMPOUNDS, 298 (1-2), 51 - 58, 英語

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    研究論文(学術雑誌)

  • Magnetism and transport properties of Nd6Fe13-xAl1+x crystals

    Y Nagata, M Kamonji, M Kurihara, S Yashiro, H Samata, S Abe

    Nd6Fe13-xAl1+x (x=2.2 and 3.5) crystals were grown by the self-flux method, and their crystallographic, magnetic and electric properties were investigated. Nd6Fe13-xAl1+x, which crystallizes in a tetragonal structure of space-group I4/mcm, shows peculiar successive magnetic transitions. In particular, Nd6Fe9.5Al4.5 shows transitions at 20 K, 56 K and 128 K, and the spontaneous magnetization M-s at 5 K (87.5 emu/g) can be explained by assuming ferromagnetic Fe sublattices (4d up arrow 16k up arrow 16l, up arrow 16l(2)up arrow) and ferrimagnetic Nd sublattices (8f down arrow 16l up arrow). Nd6Fe9.5Al4.5 seems to adopt ferrimagnetism in which the spontaneous magnetization is parallel to the [100] directions at temperatures below 20 K. A small ferromagnetic moment component, which is induced by canting of the antiferromagnetically coupled spins along the [001] direction, exists in the [100] direction at temperatures of 20 K<T<56 K. At temperatures of 56 K<T<128 K, an antiferromagnetic spin configuration exists along the [001] direction. A first-order magnetization process was observed in the magnetization curve measured in the [001] direction in the temperature ranges 20 K<T<56 K. The electrical resistivity showed anomalies at the temperatures of each magnetic transition. Moreover, a remarkable hysteresis was observed in the field dependence of resistivity. The magnetic phase transitions seem to have significant effects on the transport properties. (C) 2000 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 2000年01月, JOURNAL OF ALLOYS AND COMPOUNDS, 296 (1-2), 209 - 218, 英語

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    研究論文(学術雑誌)

  • Normal-state transport properties of Ba1-xKxBiO3 crystals

    Y Nagata, A Mishiro, T Uchida, M Ohtsuka, H Samata

    The normal-state transport properties of Ba1-xKxBiO3 crystals with a wide range of potassium compositions (0 less than or equal to x less than or equal to 0.62) were studied. Although the host material BaBiO3 has a monoclinic structure, the system changes from a monoclinic to an orthorhombic structure with a small doping of potassium (0 less than or equal to x 0.35) and behaves similar to a doped semiconductor, without exhibiting superconductivity. In the composition range, holes are majority carriers in the transport phenomena. When x exceeds a critical value (similar to 0.35), the system goes into a cubic superconducting phase with a single metallic band. The vicinity of the critical composition transport phenomena is easy to understand assuming the existence of two conducting channels that are made up of metallic and semiconducting phases. Maximum T-c exceeding 30 K was observed at x similar to 0.4, where carrier density was at its maximum. Overdoping with potassium suppresses superconductivity. In the metallic composition of x > 0.45, transport seems to correlate with the phonon mode with an energy distribution of 15-43 meV. (C) 1999 Elsevier Science Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 1999年12月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 60 (12), 1933 - 1942, 英語

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    研究論文(学術雑誌)

  • Magnetism and transport properties of Hf1-xTaxFe2 and Mn2-xCrxSb

    Y Nagata, T Hagii, S Yashiro, H Samata, S Abe

    The magnetism and transport properties of Hf1 - xTaxFe2 (0.1 less than or equal to x less than or equal to 0.2) and Mn2 - xCrxSb (x=0.1) were studied. Hf1 - xTaxFe2 (x>0.15) has a successive magnetic transition from ferromagnetism to paramagnetism via antiferromagnetism at temperatures between 150 and 350 K, and the transition has a considerable effect on the transport property. in particular, a specimen with x=0.155 shows a metamagnetic transition near room temperature, and a significant magnetoresistance as large as 12% is observed in accordance with the metamagnetic transition. Mn1.9Cr0.1Sb, which has a first-order magnetic transition from antiferromagnetism to ferrimagnetism at about 300 K, also shows a field-induced magnetic transition at 300 K, and the transition strongly affects the transport property. A giant magnetoresistance as large as 30% was observed at about 300 K under an applied field of 20 kOe. The metamagnetic transition seems to give rise to giant magnetoresistance via s-d scattering. (C) 1999 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 1999年11月, JOURNAL OF ALLOYS AND COMPOUNDS, 292 (1-2), 11 - 20, 英語

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    研究論文(学術雑誌)

  • Doping dependence of the electronic structure of Ba1-xKxBiO3 studied by x-ray-absorption spectroscopy

    K Kobayashi, T Mizokawa, A Ino, J Matsuno, A Fujimori, H Samata, A Mishiro, Y Nagata, FMF de Groot

    We have performed x-ray-absorption spectroscopy (XAS) and x-ray-photoemission spectroscopy (XPS) studies of single crystal Ba1-xKxBiO3 (BKBO) covering the whole composition range 0 less than or equal to x less than or equal to 0.60. Several features in the oxygen 1s core XAS spectra show systematic changes with x. Spectral weight around the absorption threshold increases with hole doping and shows a finite jump between x=0.30 and 0.40, which signals the metal-insulator transition. We have compared the obtained results with band-structure calculations. Comparison with the XAS results of BaPb1-xBixO3 has revealed quite different doping dependences between BKBO and BPBO. We have also observed systematic core-level shifts in the XPS spectra as well as in the XAS threshold as functions of x, which can be attributed to a chemical potential shift accompanying the hole doping. The observed chemical potential shift is found to be slower than that predicted by the rigid band model based on the band-structure calculations. [S0163-1829(99)01023-1].

    AMER PHYSICAL SOC, 1999年06月, PHYSICAL REVIEW B, 59 (23), 15100 - 15106, 英語

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    研究論文(学術雑誌)

  • Magnetic anisotropy and magnetostriction of SmFe2 crystal

    H Samata, N Fujiwara, Y Nagata, T Uchida, MD Lan

    Magnetic anisotropy and magnetostriction of SmFe2 crystal were studied. Crystals were group by a self-flux method using Sm as a flux. Magnetic anisotropy and magnetostriction were measured by means of a torque magnetometer and a new optical technique, respectively. SmFe2 shows a typical cubic anisotropy with anisotropy constants K-1 = -5.3 x 10(6) and K-2 = 1.9 x 10(6) erg/cm(3) at 300 K. Though the easy axis of magnetization is parallel to the [1 1 0] direction at low temperatures, it changes to the [1 1 1] direction at temperatures above 195 K. Magnetostriction constants were determined to be lambda(111) - 2010 x 10(-6), lambda(100) = -130 x 10(-6) and lambda(s) = -1258 x 10(-6) at 300 K. The magnetoelastic contribution Delta K-1 (similar to-8.8 x 10(6) erg/cm(3)) to the anisotropy constant seems to be larger than the intrinsic anisotropy constant K-1 (int) (similar to 3.5 x 10(6) erg/cm(3)) in SmFe2. If this is the case;easy axis of magnetization has been changed from the [1 0 0] direction (K-1 int > 0) to the [1 1 1] direction (effective anisotropy K-1 (eff) - K-1 int + Delta K-1 < 0) at 300 K by a large magnetoelastic contribution. (C) 1999 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 1999年05月, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 195 (2), 376 - 383, 英語

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    研究論文(学術雑誌)

  • Magnetism and transport properties of metamagnetic Mn1-xCrxAu2

    Y Nagata, T Hagii, H Samata, T Uchida, S Abe, CF Sung, MD Lan

    Crystallographic, magnetic and electric properties of metamagnetic Mn1-xCrxAu2 were studied. Pure MnAu2 has a helical-spin structure and the structure changes to a ferromagnetic state below the Neel temperature T-N (similar to 360 K) and above a threshold magnetic field H-th (similar to 10 kOe at 300 K). The T-N, H-th for the metamagnetic transition, and the helical angle of the helical-spin configuration decreases as the Cr content x increases. The Cr substitution seems to dilute the magnetism of MnAu2 and to weaken the interlayer magnetic coupling between the Mn spins. A significant magnetoresistance as large as 3.5% was observed at room temperature in magnetic fields below 10 kOe. The metamagnetic transition seems to give rise to the magnetoresistance via s-d scattering. (C) 1999 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 1999年03月, JOURNAL OF ALLOYS AND COMPOUNDS, 284 (1-2), 47 - 53, 英語

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  • メロシアニンおよびフタロシアニン有機超薄膜の光電変換特性

    内田 孝幸, 大塚 正男, 井辻 健明, 佐俣 博章, 永田 勇二郎

    電気学会, 1998年12月, 電気学会論文誌A, 118-A (12), 1384 - 1390, 日本語

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  • New intermetallic compounds found in Hf-Ni-Ge and Hf-Pt-Ge systems

    Y Nagata, K Sodeyama, S Yashiro, H Sasaki, H Samata, T Uchida, MD Lan

    New intermetallic compounds, Hf3Ni4Ge4 and HfPtGe, were found and their crystallographic, electric and magnetic properties were characterized. Hf,Ni,Ge, has an orthorhombic structure (space group Immm) with lattice constants of a=1.2873 nm, b=0.6484 nm, and c=0.3892 nm and shows typical Curie-paramagnetic behavior between 2 K and 300 K and a metallic temperature dependence of the resistivity at temperatures between 10 and 250 K. HfPtGe has an orthorhombic structure (space group Pnma) with lattice constants of a=0.6603 nm, b=0.3950 nm, and c=0.7617 nm and shows diamagnetism and a metallic temperature dependence of the resistivity. (C) 1998 Elsevier Science S.A. All rights reserved.

    ELSEVIER SCIENCE SA, 1998年12月, JOURNAL OF ALLOYS AND COMPOUNDS, 281 (2), 112 - 116, 英語

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    研究論文(学術雑誌)

  • Crystal growth and magnetic properties of SmFe2

    H Samata, N Fujiwara, Y Nagata, T Uchida, M Der Lan

    SmFe2 crystals were grown by the self-flux method using Sm as a flux, and the crystallographic and magnetic properties of the crystal were studied for the first time. SmFe2 crystallizes in a cubic MgCu2-type structure (space group of Fd3m) with lattice constants of a = 0.7425 nm. Saturation magnetization M-S at 5 K and 300K and the Curie temperature of SmFe2 are 64.4 emu/g, 59.8 emu/g, and 669 It, respectively The easy-direction of the magnetization is parallel to the [110] direction of the cubic crystal at 300 K, but it: changes to the [111] direction at about 195 K.

    JAPAN J APPLIED PHYSICS, 1998年10月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 37 (10), 5544 - 5548, 英語

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    研究論文(学術雑誌)

  • Crystal growth and superconductivity of (Sm0.75Ce0.25)(2)Sr2Cu2NbO10-delta

    H Samata, S Takahashi, T Masuda, Y Nagata, T Uchida, M Ohtsuka, M Der Lan

    Single crystals of (Sm0.75Ce0.25)(2)Sr2Cu2NbO10-delta (SCSCNO) were grown by a flux method using SrCu6Oy as flux, and their morphology and superconductivity were investigated. We found that the as-grown crystal consists of SCSCNO and SmSr2Cu2NbO8 (SSCNO) crystal layers, with the SCSCNO layer being sandwiched between two non-superconducting SSCNO crystal layers. The SSCNO layers can be removed by chemical etching with HCl solution. The SCSCNO crystal shows a superconducting transition at about 17 K, and the superconducting volume fraction increased when the crystals were annealed in an oxygen atmosphere. (C) 1998 Elsevier Science Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 1998年09月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 59 (9), 1585 - 1590, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Crystal growth and properties of new ruthenium oxides

    H Samata, A Mishiro, S Sawada, Y Nagata, T Uchida, M Kai, M Ohtsuka, MD Lan

    New ruthenium oxide crystals of NaBa3Ru2O10, (Na0.57Sm0.43)Ba3Ru2O10 and (Na0.74Dy0.26)-Ba3Ru2O10 were synthesized by an electrochemical method using molten NaOH as an electrolyte, and their crystallographic, electric and magnetic properties were characterized. All the crystals have hexagonal structure of space group P6(3)mc and exhibit semiconductive behavior with activation energies of 0.19, 0.19 and 0.38 eV, respectively, for NaBa3Ru2O10, (Na0.57Sm0.43)Ba3Ru2O10 and (Na0.74Dy0.26)Ba3Ru2O10 crystals. In addition, all the crystals have negative asymptotic Curie temperatures. They appear to have antiferromagnetic orders; however, antiferromagnetic transition was not observed in the magnetization measurement down to 2 K. Effective magnetic moment P-eff was determined to be 0.49, 0.85 and 2.07 mu(B)/f.u. for NaBa3Ru2O10, (Na0.57Sm0.43)Ba3Ru2O10 and (Na0.74Dy0.26)Ba3Ru2O10. (C) 1998 Elsevier Science Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 1998年09月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 59 (9), 1445 - 1452, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Magnetic anisotropy of new intermetallic compound SmFe7

    H Samata, N Fujiwara, Y Nagata, T Uchida, MD Lan

    We characterized the magnetocrystalline anisotropy of a novel intermetallic compound, SmFe7, by means of torque measurement. Single crystal of SmFe7 was grown by the self-flux method using Sm as a flux. From an analysis of the torque curves in the (001) and (100) planes using the least mean squares method, we found that the tetragonal anisotropy constants K-1, K-2 and K-3 of SmFe7 an -8.7+/-0.4 (x 10(7) erg/cm(3)), 1.4+/-0.3 (x 10(7) erg/cm(3)), and -2.7+/- 0.1 (x 10(6) erg/cm(3)) at 293 K, respectively. The reliability of these values was confirmed using the results of magnetization measurements. The huge magnetocrystalline anisotropy of SmFe7 is superior to that of Nd2Fe14B. SmFe7 appears to he a promising host material for a high-performance hard magnet.

    JAPAN J APPLIED PHYSICS, 1998年06月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 37 (6A), 3290 - 3294, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Giant magnetoresistance observed in metamagnetic bulk-MnAu2

    H Samata, N Sekiguchi, A Sawabe, Y Nagata, T Uchida, M Der Lan

    Giant magnetoresistance (GMR) Delta rho/rho of about 10% was observed in bulk-MnAu2 at 300 K in a field of 70 kOe. MnAu2 is a tetragonal material with a spiral spin structure of Mn and shows a metamagnetic transition from a spiral to a ferromagnetic structure at an applied field of about 10 kOe at 300 K. Significant GMR was observed simultaneously with the metamagnetic transition. (C) 1997 Elsevier Science Ltd.

    PERGAMON-ELSEVIER SCIENCE LTD, 1998年03月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 59 (3), 377 - 383, 英語

    [査読有り]

    研究論文(学術雑誌)

  • x型無金属フタロシアニンを用いた有機光センサ

    大塚 正男, 内田 孝幸, 菅原 將, 佐俣 博章, 永田 勇二郎

    1997年11月, 電気学会論文誌E, 117-E (11), 537 - 544, 日本語

    [査読有り]

    研究論文(学術雑誌)

  • Electrochemical crystal growth of superconducting cuprates

    H Samata, T Komiyama, S Tsuboi, Y Nagata, T Uchida, M Ohtsuka, MD Lan

    An electrochemical method was applied to grow crystals of La2CuO4 and Nd2CuO4 at temperatures below 400 degrees C in a zirconium bath using molten NaOH as an electrolyte. The La2CuO4 crystal grown at 320 degrees C shows superconductivity with the onset transition temperature of 25 K without any heat treatment in oxygen. The results of EPMA, AES and iodometory revealed that the crystal is oxygen rich La2CuO4+delta without any substitution of La by Na. The crystals seem to be highly oxidized in the process of the electrochemical deposition. in the case of Nd2CuO4, crystals were grown at 380 degrees C. However, the substitution of Nd by a large amount of Ce was unsuccessful. (C) 1997 Elsevier Science Ltd.

    PERGAMON-ELSEVIER SCIENCE LTD, 1997年10月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 58 (10), 1547 - 1552, 英語

    [査読有り]

    研究論文(学術雑誌)

  • A new electrolysis-cell method for the synthesis of oxide crystal

    H Samata, M Furuya, A Mishiro, Y Nagata, T Uchida, M Ohtsuka, MD Lan

    A new 'Electrolysis-Cell Crystal Growth' technique for the synthesis of oxide single crystals is introduced. In this method electrolyte of molten KOH solution and metal electrodes form an electrolysis cell, and crystal growth is performed using the electromotive force of the cell itself without using any external electric power-supply. As an example, the method was applied to the crystal growth of Ba1-xKxBiO3, and the characterization of the crystal has been performed. (C) 1997 Elsevier Science Ltd.

    PERGAMON-ELSEVIER SCIENCE LTD, 1997年10月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 58 (10), 1521 - 1527, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Magnetic and superconducting properties in the Y1-xDyxNi2B2 system

    MD Lan, JL Chen, CW Hsing, H Samata, Y Nagata

    We measured the magnetic and superconducting properties in intermetallic compounds Y1-xDyxNi2B2C (0 less than or equal to x less than or equal to 1.0) over wide temperature and magnetic field ranges. The reduction of the superconducting temperature is mainly caused by the magnetic pair breaking effect due to the existence of Dy+3 paramagnetic ions. The long-range magnetic ordering for samples with high Dy composition is through the Ruderman-Kittel-Kasuya-Yosida indirect exchange interaction. The exchange interaction is strongly modulated by the Dy+3- moment separation. The small value of the Curie-Weiss temperature suggests that the coupling between the conduction electrons and the magnetic moment is not too strong. There is no evidence to show the co-existence of long-range magnetic ordering and superconductivity in the Y1-xDyxNi2B2C system. The small value of k for the Dy-doped YNi2B2C compound indicates that the Y-Ni-B-C compound is not a strongly type-II superconductor. (C) 1997 Elsevier Science Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 1997年09月, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 58 (9), 1425 - 1431, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Magnetic properties of SmFe3 single crystal

    H Samata, N Fujiwara, Y Shimizu, Y Nagata, T Uchida, MD Lan

    SmFe3 single crystal was grown by a self-flux method using Sm as a flux, and its crystallographic and magnetic properties have been studied. SmFe3 crystalizes in the rhombohedral PuNi3-type structure and has lattice constants of a = 0.5179 and c = 2.4795 nm. The saturation magnetizations M-S at 5 K and 300 K are respectively 89.9 emu/g and 80.7 emu/g, and the Curie temperature is 644 K. The anisotropy constants K-1 and K-2 at 5 K are -2.69 x 10(7) and 11.9 x 10(7) erg/cm(3) and at 300 K are 2.36 x 10(7) and 2.21 x 10(7) erg/cm(3). While the easy direction of magnetization is parallel to the c-axis at 300 K, it lies on the surface of a cone below 160 K. The angle theta between the c-axis and the generatrix of the cone is about 310 at 5 K.

    JAPAN J APPLIED PHYSICS, 1997年06月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 36 (6A), 3492 - 3496, 英語

    [査読有り]

    研究論文(学術雑誌)

  • New intermetallic compound found in Sm-Fe system

    H Samata, Y Satoh, Y Nagata, T Uchida, M Kai, MD Lan

    A new intermetallic compound. SmFe7, has been found in the Sm-Fe system. We grew SmFe7 single crystals via a self-flux method. Precise X-ray analysis revealed that SmFe7 has a tetragonal structure with a space group of P4(2)/mnm and lattice constants of a = 0.8765 and c = 1.2133 nm, The structure is very similar to that of R2Fe14B (R=rare earth) except that the boron sites of R2Fe14B are vacant. Magnetization measurement results suggest that SmFe: is a ferrimagnet with a significantly large spontaneous magnetization (136 emu/g at 293 K) and a huge anisotropy constant (K-1 + K-2 similar to -6.9 x 10(7) erg/cc at 293 K).

    JAPAN J APPLIED PHYSICS, 1997年04月, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 36 (4B), L476 - L478, 英語

    [査読有り]

    研究論文(学術雑誌)

  • 電気化学合成法による広いK組成範囲をもつBa1-xKxBiOy単結晶の作製と評価

    内田 孝幸, 大塚 正男, 古矢 雅彦, 佐俣 博章, 永田 勇二郎

    1995年12月, 電気学会論文誌A, 115-A (12), 1278 - 1283, 日本語

    [査読有り]

    研究論文(学術雑誌)

  • Yuichi Furuyama, Hodaka Nakamura, Tsubasa Takeda, Hiroaki Samata, Akira Taniike, Akira Kitamura

    In order to investigate the CO2 absorption characteristics of the low- and high-density Li2TiO3 samples, X-ray diffraction (XRD), non-Rutherford backscattering spectroscopy (NRBS) and elastic recoil detection (ERD) analyses have been performed. Crystallographic structure of a sintered and CO2 exposed samples is decided by the XRD analysis, and the NRBS and ERD analyses have evaluated the amount of CO2 absorption and H content quantitatively. The CO2 absorption characteristics of the non-stoichiometric Li2TiO3 sample are investigated. It is found that the CO2 absorption rate of the non-stoichiometric Li2TiO3 sample is much larger than that of the stoichiometric sample. The Li2TiO3 sample (80%T.D.) has a good tritium release characteristics, and we find also that the sample sintered at temperatures higher than 1,428 K absorb very little CO2 under high humidity conditions. The amount of CO2 absorption of the low-density Li2TiO3 samples is found to increase with increase in the humidity. This seems to be a catalytic effect of water vapor on CO2 absorption at the Li2TiO3 surface.

    Elsevier Ltd, 2018年05月01日, Nuclear Materials and Energy, 15, 164 - 168, 英語

    [査読有り]

    研究論文(学術雑誌)

MISC

  • 光ファイバ-変位計測の原理を用いた磁歪の測定

    佐俣 博章, 永田 勇二郎

    アグネ技術センタ-, 1998年10月, 固体物理, 33 (10), 841 - 844, 日本語

  • 26aPS-47 EuOOHのVan Vleck常磁性(26aPS 領域3ポスターセッション,領域3(磁性,磁気共鳴))

    佐俣 博章, 和田 直樹, 水崎 壮一郎, 永田 勇二郎, 小澤 忠司

    一般社団法人日本物理学会, 2013年03月26日, 日本物理学会講演概要集, 68 (1), 509 - 509, 日本語

  • 20pCD-4 反強磁性体Ru_2MnGeのV置換による強磁性(20pCD 遍歴磁性・酸化物磁性,領域3(磁性,磁気共鳴))

    水崎 壮一郎, 堂園 明, 大西 智弘, 佐俣 博章, 野呂 良彦, 伊藤 真義, 櫻井 吉晴, 永田 勇二郎

    一般社団法人日本物理学会, 2012年08月24日, 日本物理学会講演概要集, 67 (2), 436 - 436, 日本語

  • 20pQG-11 ホイスラー型金属間化合物における異方性磁気抵抗効果(20pQG 化合物・酸化物磁性,領域3(磁性,磁気共鳴))

    水崎 壮一郎, 堂園 明, 永田 勇二郎, 小澤 忠, 野呂 義彦, 佐俣 博章

    一般社団法人日本物理学会, 2008年08月25日, 日本物理学会講演概要集, 63 (2), 366 - 366, 日本語

  • 電気化学的合成法による酸化物超伝導体Ba_1-_XK_XBiO_3の単結晶の作製と評価

    佐俣 博章, 坂本 研也

    神戸大学, 2001年07月, 神戸商船大学紀要. 第二類, 商船・理工学篇, 49, 71 - 76, 日本語

  • Flux-Creep-up法による希土類-鉄系金属間化合物の単結晶の育成

    佐俣 博章, 坂本 研也

    神戸大学, 2000年07月, 神戸商船大学紀要. 第二類, 商船・理工学篇, 48, 55 - 60, 日本語

  • 金属間化合物単結晶SmFe_2の結晶磁気異方性と磁歪

    佐俣 博章, 永田 勇二郎

    1998年09月01日, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 378 - 378, 日本語

  • 市販トルクセンサを用いた簡単な磁気トルク測定装置

    佐俣 博章, 本多 洋介, 永田 勇二郎

    アグネ技術センタ-, 1998年06月, 固体物理, 33 (6), 541 - 544, 日本語

  • Sm-Fe系金属間化合物単結晶の磁気特性

    佐藤 恭央, 佐俣 博章, 永田 勇二郎, 内田 孝幸

    1995年09月01日, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 19, 461 - 461, 日本語

  • 水崎 壮一郎, 平岡 望, 小澤 忠, 佐俣 博章, 野呂 良彦, 大西 智弘, 岡田 直哉, 永田 勇二郎, 谷口 貴士, 伊藤 真義, 櫻井 吉晴, 児玉 謙司, 中村 哲也

    一般社団法人 日本物理学会, 2010年, 日本物理学会講演概要集, 65 (0), 556 - 556, 日本語

講演・口頭発表等

  • ZnMoO4: Eu3+ と ZnWO4 の蛍光特性に対するインターカレーションの影響

    伊井大介, 佐俣 博章

    第66回応用物理学会春季学術講演会, 2019年03月, 日本語, 国内会議

    ポスター発表

  • Y0.90-xYbxEr0.10BaZn3AlO7の波長変換コンポジット膜の作製と評価

    埴岡正史, 佐俣 博章

    第66回応用物理学会春季学術講演会, 2019年03月, 日本語, 国内会議

    ポスター発表

  • 神戸大タンデム加速器の現状2018

    谷池 晃, 蔭山 博之, 横瀬 豊司, 古山 雄一, 劉 秋生, 佐俣 博章

    第31回タンデム加速器及びその周辺技術の研究会, 2018年07月, 日本語, 東京都市大学 二子玉川夢キャンパス, 国内会議

    口頭発表(一般)

  • 2波長光照射時のY0.70Yb0.20Er0.10BaZn3AlO7 の波長変換特性

    埴岡正史, 佐俣 博章

    第65回応用物理学会春季学術講演会, 2018年03月, 日本語, 早稲田大学, 国内会議

    ポスター発表

  • インターカレショによるNa2Ti3O7: Eu3+とK2Ti2O5 の蛍光特性制御

    安田拓巳, 伊井大介, 佐俣 博章

    第65回応用物理学会春季学術講演会, 2018年03月, 日本語, 早稲田大学, 国内会議

    ポスター発表

  • RE3+添加型Gd-AE-Al系酸化物のUC発光の温度消光特性

    西村優輝, 広岡誠, 佐俣 博章

    第65回応用物理学会春季学術講演会, 2018年03月, 日本語, 早稲田大学, 国内会議

    ポスター発表

  • Bi添加型Na-Al系リン酸塩化合物の青色発光特性

    草薙一斗, 佐俣 博章

    第65回応用物理学会春季学術講演会, 2018年03月, 日本語, 早稲田大学, 国内会議

    ポスター発表

  • Y0.90-xYbxEr0.10BaZn3AlO7 の双方向波長変換特性

    埴岡正史, 佐俣 博章

    第78回応用物理学会秋季学術講演会, 2017年09月, 日本語, 国内会議

    ポスター発表

  • ランタノイド添加型 Gd2SrAl2O7 の合成と蛍光特性の評価

    広岡誠, 佐俣 博章

    第64回応用物理学会春季学術講演会, 2017年03月, 日本語, 国内会議

    ポスター発表

  • Gd2O3: Er3+, Yb3+ のアップ・ダウンコンバージョン特性

    埴岡正史, 佐俣 博章

    第77回応用物理学会秋季学術講演会, 2016年09月, 日本語, 国内会議

    ポスター発表

  • RE2Ba2Zn6Al2O13+δ: Yb3+, Er3+ (RE = Y, Gd) のアップコンバージョン特性

    古川 雄亮, 佐俣 博章, 小澤 忠司, 松下 能孝

    第63回応用物理学会春季学術講演会, 2016年03月, 日本語, 国内会議

    口頭発表(一般)

  • Gd2O3: Yb3+, Er3+ の下方変換発光におけるエネルギー伝達機構

    植田史郎, 有本聖吾, 佐俣 博章, 小澤忠司

    応用物理学会春季学術講演会, 2015年03月, 日本語, 国内会議

    ポスター発表

  • Gd2O3 : Er3+, Yb3+, Li+ のアップコンバージョン特性

    埴岡正史, 佐俣 博章, 有本聖吾, 小澤忠司

    応用物理学会春季学術講演会, 2015年03月, 日本語, 国内会議

    ポスター発表

  • 熱電変換モジュール用Mn系酸化物の電気化学的結晶合成

    庄野里佳子, 佐俣 博章

    日本熱電学会学術講演会, 2014年09月, 日本語, 国内会議

    ポスター発表

  • ランタノイドのオキシ水酸化物のVan Vleck常磁性

    和田直樹, 佐俣 博章

    日本磁気学会学術講演会, 2014年09月, 日本語, 国内会議

    口頭発表(一般)

  • Gd2O3: Tb3+, Yb3+ のアップコンバージョン特性

    有本 聖吾, 今中 俊吾, 川尻 庸資, 植田 史郎, 佐俣 博章, 小澤 忠司

    応用物理学会春季学術講演会, 2014年03月, 日本語, 青山学院大学相模原キャンパス, 国内会議

    ポスター発表

  • GdOOH をホスト相とした同時置換型結晶の蛍光特性

    今中 俊吾, 佐俣 博章, 有本 聖吾, 小澤 忠司

    日本物理学会秋季大会, 2013年09月, 日本語, 徳島大学常三島キャンパス, 国内会議

    ポスター発表

  • EuOOH の Van Vleck 常磁性

    佐俣 博章, 和田直樹, 水崎壮一郎, 永田勇二郎, 小澤忠司

    日本物理学会, 2013年03月, 日本語, 広島大学, 国内会議

    ポスター発表

  • 反強磁性体 Ru2MnGe の V 置換による強磁性

    水崎壮一郎, 堂園明, 大西智弘, 佐俣 博章, 野呂良彦, 伊藤真義, 櫻井吉晴, 永田勇二郎

    日本物理学会, 2012年09月, 日本語, 横浜国立大学, 国内会議

    ポスター発表

  • Gd1-x-yRExEuyOOH (RE : 希土類イオン) の蛍光特性

    小林 克年, 佐俣 博章, 永田 勇二郎, 水崎 壮一郎, 小澤 忠

    日本物理学会, 2011年09月, 日本語, 富山大学, 国内会議

    ポスター発表

  • 置換型酸化物 BaMn1-xRuxO3 と Ba1-ySryMnO3 の電気化学的結晶合成と評価

    堀 太一, 佐俣 博章, 永田 勇二郎, 水崎 壮一郎, 小澤 忠

    日本セラミック協会年会, 2011年03月, 日本語, 静岡大学, 国内会議

    ポスター発表

  • ホイスラー型合金 Ru2VAl 系の磁性及び輸送現象

    水崎 壮一郎, 大西 智弘, 佐俣 博章, 野呂 良彦, 永田 勇二郎

    日本物理学会, 2011年03月, 日本語, 新潟大学, 国内会議

    口頭発表(一般)

  • Sm, Tb を同時置換した Gd1-xEuxOOH の蛍光特性

    小林 克年, 板倉 大祐, 佐俣 博章, 永田 勇二郎, 水崎 壮一郎, 小澤 忠

    日本物理学会, 2011年03月, 日本語, 新潟大学, 国内会議

    ポスター発表

  • PVDF を用いたフッ化による A2CuO3 (A = Ca, Sr, Ba) の構造制御

    原 京太郎, 佐俣 博章, 永田 勇二郎, 水崎 壮一郎, 小澤 忠

    日本セラミック協会年会, 2011年03月, 日本語, 静岡大学, 国内会議

    ポスター発表

  • Li2-xPd1-yNiyO2-dの合成と輸送特性

    田中 賢, 辻 和宏, 佐俣 博章, 永田 勇二郎, 水崎 壮一郎, 小澤 忠

    日本物理学会, 2011年03月, 日本語, 新潟大学, 国内会議

    ポスター発表

  • CaTO3 (T=Mn, Ru, Ti) 系多層膜の作成とその物性(その2)

    瀬谷 謙太, 大西 智弘, 水崎 壮一郎, 小澤 忠, 野呂 良彦, 佐俣 博章, 永田 勇二郎

    応用物理学関係連合講演会, 2011年03月, 日本語, 神奈川工科大学, 国内会議

    口頭発表(一般)

  • Ca1-xSrxRu0.5Mn0.5O3 系の導電性と熱起電力

    大西 智弘, 水崎 壮一郎, 内藤 誠, 小澤 忠, 野呂 良彦, 佐俣 博章, 永田 勇二郎

    応用物理学関係連合講演会, 2011年03月, 日本語, 神奈川工科大学, 国内会議

    口頭発表(一般)

  • ホイスラー型合金 Ru2VGa 系の磁性及び輸送現象

    水崎 壮一郎, 大西 智弘, 佐俣 博章, 野呂 良彦, 永田 勇二郎

    日本物理学会, 2010年09月, 日本語, 大阪府立大学, 国内会議

    ポスター発表

  • T2XY-system の熱電性能特性

    大西 智弘, 猪股 勇, 佐藤 宏亮, 水崎 壮一郎, 小澤 忠, 野呂 良彦, 佐俣 博章, 永田 勇二郎

    応用物理学会, 2010年09月, 日本語, 長崎大学, 国内会議

    ポスター発表

  • Synthesis and Fluorescence Quantum Yield of Gd1-xLnxOOH (Ln = Eu, Tb) Crystals

    佐俣 博章, D. Itakura, K. Kobayashi, S. Mizusaki, Y. Nagata, T.C. Ozawa

    Seventh International Conference on Inorganic Materials, 2010年09月, 英語, Biarritz, France, 国際会議

    ポスター発表

  • CaTO3 (T=Mn, Ru, Ti) 系多層膜の作成とその物性

    瀬谷 謙太, 大西 智弘, 水崎 壮一郎, 小澤 忠, 野呂 良彦, 佐俣 博章, 永田 勇二郎

    応用物理学会, 2010年09月, 日本語, 長崎大学, 国内会議

    口頭発表(一般)

  • Gd1-xEuxOOH の合成と量子収率の評価

    板倉 大祐, 佐俣 博章, 水崎 壮一郎, 永田 勇二郎, 小澤 忠

    日本セラミック協会年会, 2010年03月, 日本語, 東京農工大学, 国内会議

    口頭発表(一般)

  • CaRuO3 の Fe 置換による強磁性発現における Ru の磁気状態

    水崎 壮一郎, 大西 智弘, 岡田 直哉, 永田 勇二郎, 谷口 貴士, 伊藤 真義, 櫻井 吉晴, 児玉 謙司, 中村 哲也, 平岡 望, 小澤 忠, 佐俣 博章, 野呂 良彦

    日本物理学会, 2010年03月, 日本語, 岡山大学(津島キャンパス), 国内会議

    口頭発表(一般)

  • The spin moment of SmFe7 observed by magnetic Compton scattering

    S. Mizusaki, T. Ohnishi, Y. Kozaki, Y. Nagata, M. Itou, Y. Sakurai, Y. Noro, H. Samata

    IEEE International Magnetics Conference, 2009年05月, 英語, Sacramento, California, 国際会議

    ポスター発表

  • ホイスラー型合金 Ru2Ti1-xFexGe の磁気的および電気的性質

    廣瀬 誠, 水崎 壮一郎, 永田 勇二郎, 小澤 忠司, 野呂 良彦, 佐俣 博章

    第56回応用物理学関係連合講演会, 2009年04月, 日本語, 筑波大学(筑波キャンパス), 国内会議

    口頭発表(一般)

  • ホイスラー型合金 Co2[Cr, Ti]Al の磁気的性質

    水崎 壮一郎, 堂園 明, 大西 智弘, 永田 勇二郎, 小澤 忠司, 野呂 義彦, 佐俣 博章

    第56回応用物理学関係連合講演会, 2009年04月, 日本語, 筑波大学(筑波キャンパス), 国内会議

    口頭発表(一般)

  • CaRu1−xMnxO3 及び Ca1−xSrxRuO3 の電気化学的結晶合成と評価

    佐伯 雄大, 堀 太一, 佐俣 博章, 水崎 壮一郎, 永田 勇二郎, 小澤 忠, 佐藤 晃

    日本セラミック協会, 2009年03月, 日本語, 東京理科大学(野田キャンパス), 国内会議

    口頭発表(一般)

  • リン酸塩ガラスのプロトン伝導とラマン散乱

    豊田 泰文, 水崎 壮一郎, 永田 勇二郎, 佐俣 博章, 小澤 忠, 野呂 良彦

    応用物理学会学術講演会, 2008年09月, 日本語, 国内会議

    口頭発表(一般)

  • ホイスラー型合金 Ru2T1-xT’xGe (T=Mn, Fe;T’=Ti, V) の磁気特性

    堂園 明, 水崎 壮一郎, 永田 勇二郎, 小澤 忠司, 野呂 良彦, 佐俣 博章

    応用物理学会学術講演会, 2008年09月, 日本語, 国内会議

    口頭発表(一般)

  • ホイスラー型金属間化合物における異方性磁気抵抗効果

    水崎 壮一郎, 堂園 明, 永田 勇二郎, 小澤 忠, 野呂 良彦, 佐俣 博章

    日本物理学会, 2008年09月, 日本語, 国内会議

    口頭発表(一般)

  • Electrochemical crystal growth of perovskite ruthenates

    H. Samata, Y. Saeki, S. Mizusaki, Y. Nagata, T.C. Ozawa, A. Sato

    The 4th Asian Conference on Crystal Growth and Crystal Technology, 2008年05月, 英語, 国際会議

    ポスター発表

  • 金属間化合物Ru2Fe(Si,Ge)における磁気構造と磁気抵抗効果の相関

    水崎 壮一郎, 堂園 明, 永田 勇二郎, 佐俣 博章, 小澤 忠, 野呂 良彦

    応用物理学関係連合講演会, 2008年03月, 日本語, 国内会議

    口頭発表(一般)

  • 希土類・遷移金属・燐系3元系金属間化合物結晶の作成と物性

    大西 智弘, 水崎 壮一郎, 永田 勇二郎, 佐俣 博章, 小澤 忠, 野呂 良彦

    応用物理学関係連合講演会, 2008年03月, 日本語, 国内会議

    口頭発表(一般)

  • ホイスラー型合金Ru2Mn1-xFexGeの異方的磁気抵抗効果

    堂園 明, 水崎 壮一郎, 永田 勇二郎, 小澤 忠司, 野呂 良彦, 佐俣 博章

    応用物理学関係連合講演会, 2008年03月, 日本語, 国内会議

    口頭発表(一般)

  • プロトン導電性を有する新しいリン酸塩ガラスの合成と特性の評価

    豊田 泰文, 水崎 壮一郎, 永田 勇二郎, 佐俣 博章, 小澤 忠, 野呂 良彦

    応用物理学関係連合講演会, 2008年03月, 日本語, 国内会議

    口頭発表(一般)

  • Near room temperature ferromagnetism in Sr and Mn doped CaRuO3

    M. Naito, S. Mizusaki, T. Taniguchi, Y. Nagata, T.C. Ozawa, Y. Noro, H. Samata

    52nd Magnetism and Magnetic Materials Conference, 2007年11月, 英語, Florida, USA, 国際会議

    ポスター発表

  • Magnetism of CaRu1-xMnxO3 studied by magnetic Compton scattering

    S. Mizusaki, T. Taniguchi, N. Okada, Y. Nagata, M. Itou, Y. Sakurai, T.C. Ozawa, Y. Noro, H. Samata

    52nd Magnetism and Magnetic Materials Conference, 2007年11月, 英語, Florida, USA, 国際会議

    ポスター発表

  • 電気化学的手法によるランタノイドの酸化水酸化物の結晶合成

    木村 大輔, 佐俣 博章, 永田 勇二郎, 小澤 忠

    日本物理学会, 2007年09月, 日本語, 国内会議

    ポスター発表

  • 層状酸化物Li2-xMgxRuO3の合成と評価

    達川 永吾, 佐俣 博章, 永田 勇二郎, 小澤 忠

    日本物理学会, 2007年09月, 日本語, 国内会議

    ポスター発表

  • ホイスラー型合金Ru2[Mn,Fe]Geの磁気的性質

    水崎 壮一郎, 大西 智弘, 谷口 貴士, 永田 勇二郎, 小澤 忠司, 野呂 良彦, 佐俣 博章

    第68回応用物理学会, 2007年09月, 日本語, 国内会議

    口頭発表(一般)

  • ペロブスカイト酸化物(Sr,Ca)[Ru,Mn]O3の磁気的および電気的性質

    内藤 誠, 水崎 壮一郎, 谷口 貴士, 永田 勇二郎, 小澤 忠司, 野呂 良彦, 佐俣 博章

    第68回応用物理学会, 2007年09月, 日本語, 国内会議

    口頭発表(一般)

  • スピンコート法により作製したCa(Ru, M)O3 (M=3d遷移金属) 系エピタキシャル膜の物性

    小河原 正晴, 水崎 壮一郎, 谷口 貴史, 永田 勇二郎, 小沢 忠司, 野呂 良彦, 佐俣 博章

    第68回応用物理学, 2007年09月, 日本語, 国内会議

    口頭発表(一般)

  • TRANSPORT AND MAGNETIC PROPERTIES OF CaRu1-xMxO3 (M=Fe or Mn) EPITAXIAL FILMS

    TANIGUCHI T, MIZUSAKI S, FUKUOKA N, NAGATA Y, NORO Y, SAMATA Hiroaki

    International Conference on Magnetism, 2006年08月, 英語, Kyoto, Japan, 国際会議

    ポスター発表

  • THE DIRECT OBSERVATION OF THE MAGNETIC SPIN COMPONENT OF SAMARIUM-IRON BASED LAVES COMPOUND BY MAGNETIC COMPTON SCATTERING

    MIZUSAKI S, KAWAMURA N, TANIGUCHI T, ITOU M, SAMATA Hiroaki, NORO Y, SAKURAI Y, NAGATA Y

    International Conference on Magnetism, 2006年08月, 英語, Kyoto, Japan, 国際会議

    ポスター発表

  • Synthesis and Characterization of Multi Nano-block Layer Integrated Magnetic Compounds

    OZAWA Tadashi C, IKOSHI A, TANIGUCHI T, MIZUSAKI S, NAGATA Y, NORO Y, SAMATA Hiroaki

    3rd International Symposium on Bioscience and Nanotechnology, 2005年11月, 英語, Miyazaki, Japan, 国際会議

    ポスター発表

  • 紫外線照射中のSiナノ粒子添加型導波路の in situ損失測定

    中根 暢隆, 田口 哲也, 佐俣 博章, 西井 準治

    応用物理学会学術講演会, 2005年09月, 日本語, 応用物理学会学, 徳島大学, 国内会議

    口頭発表(一般)

  • UV-induced Excess Loss of Er- and Si-nanocrystal Co-doped Silica Waveguide for Optical Amplifier

    NISHII Junji, SE-WEON Choi, HOSONO Hideo, TAGUCHI Tetsuya, NAKANE Nobutaka, SAMATA Hiroaki, OSHITANI Yuma, SAITO Mitsunori

    31st European Conference on Optical Communication, 2005年09月, 英語, Glasgow, Scotland, 国際会議

    口頭発表(一般)

  • Siナノ粒子とEr3+を共添加したSiO2薄膜のLED励起による蛍光特性

    田口 哲也, 中根 暢隆, 佐俣 博章, 西井 準治

    応用物理学会学術講演会, 2005年09月, 日本語, The Japan Society of Applied Physics, 徳島大学, 国内会議

    口頭発表(一般)

  • Epitaxial ABO3-type Oxide Films Prepared by the Sol-Gel Method

    TANIGUCHI Takashi, FUKUOKA Naoto, OZAWA Tadashi C, NAGATA Yujiro, NORO Yoshihiko, SAMATA Hiroaki

    IEEE International Magnetics Conference, 2005年04月, 英語, The Magnetics Society of Japan, The Magnetics Society of the IEEE, Nagoya, Japan, 国際会議

    ポスター発表

  • 電気化学的手法を利用した基板上への酸化物の結晶成長

    石森 周一, 佐俣 博章, 谷口 貴士, 永田 勇二郎

    日本物理学会, 2004年09月, 日本語, 青森大学, 国内会議

    ポスター発表

  • 電気化学的手法による酸化物の低温合成を利用した新物質探索の試み

    和泉 裕也, 佐俣 博章, 谷口 貴士, 永田 勇二郎

    日本物理学会, 2004年09月, 日本語, 青森大学, 国内会議

    ポスター発表

  • Insulator to Metal Transition in Sr1-xNaxPd3O4

    TANIGUCHI T, NAGATA Y, OZAWA T.C, SATO M, NORO Y, SAMATA Hiroaki

    Fourth International Conference on Inorganic Materials, 2004年09月, 英語, University of Antwerp, Belgium, 国際会議

    ポスター発表

  • 3d遷移金属元素を含むペロブスカイト型酸化物における元素置換効果

    稲川 憲司, 佐俣 博章, 谷口 貴士, 永田 勇二郎

    日本物理学会, 2004年09月, 日本語, 青森大学, 国内会議

    ポスター発表

  • 電磁波推進船等に用いる新しい超伝導材料の開発に関する基礎的研究

    佐俣 博章, 武田 実, 山本 茂広, 赤澤 輝彦

    2003年度神戸大学海事科学部プロジェクト研究報告会要旨集 pp.75-78, 2004年, 日本語, 神戸大学海事科学部, 未記入, 国内会議

    口頭発表(一般)

  • La2ZnTiO6: Nd3+, Yb3+, Ho3+ の近赤外光励起時のアップコンバージョン特性

    安岡真理, 佐俣博章

    第69回応用物理学会春季学術講演会, 2022年03月22日

  • Al リン酸塩化合物における O-F 八面体中の Ti4+ の発光特性

    細井飛呂, 佐俣博章

    第82回応用物理学会秋季学術講演会, 2021年09月10日

  • SrLaZnO3.5 をホストとした双方向波長変換膜の a-Si 太陽電池への応用

    首藤利来, 佐俣博章

    第82回応用物理学会秋季学術講演会, 2021年09月10日

  • 可視光励起による RE2BaZnO5 (RE = Y, La): Pr3+ の紫外発光特性

    岡本尚大, 岩崎智志, 田村加奈葉, 佐俣博章

    第82回応用物理学会秋季学術講演会, 2021年09月10日

  • 添加型 Ca8Mg(SiO4)4Cl2 の結晶合成と双方向波長変換特性

    則光勝雄, 佐俣博章

    第81回応用物理学会秋季学術講演会, 2020年09月09日

  • YBaZn3AlO7: Er3+, Yb3+ コンポジット膜のa-Si太陽電池への応用

    芳村亮弥, 首藤利来, 佐俣博章

    第81回応用物理学会秋季学術講演会, 2020年09月09日

  • 水熱合成した賦活剤添加 Na3Al2(PO4)2F3 の蛍光特性

    浮田治基, 佐俣博章

    第80回応用物理学会秋季学術講演会, 2019年09月19日

所属学協会

  • 電気学会

  • 日本応用磁気学会

  • 応用物理学会

共同研究・競争的資金等の研究課題