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Dependence of Valence Fluctuation and Physical Anomalies on the Degree of Order in Pd-Ce Ordering Alloys

Research Project

Project/Area Number 01550511
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field Physical properties of metals
Research InstitutionKyushu University

Principal Investigator

OKI Kensuke  Kyushu University, Graduate School of Engineering Sciences, Professor, 総合理工学研究科, 教授 (70037860)

Co-Investigator(Kenkyū-buntansha) ITAKURA Masaru  Kyushu University, Graduate School of Engineering Sciences, Research Associate, 総合理工学研究科, 助手 (20203078)
MATSUMURA Syo  Kyushu University, Graduate School of Engineering Sciences, Research Associate, 総合理工学研究科, 助手 (60150520)
KUWANO Noriyuki  Kyushu University, Graduate School of Engineering Sciences, Associate Professor, 総合理工学研究科, 助教授 (50038022)
Project Period (FY) 1989 – 1990
Project Status Completed (Fiscal Year 1990)
Budget Amount *help
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥1,700,000 (Direct Cost: ¥1,700,000)
KeywordsPalladium Cerium alloy / Concentrated Kondo effect / 4f-electron / Valenece fluctuation / Annealing temperature effect / Ordering alloy / Physical anomaly / 希土類 / X線吸収端近傍構造 / パラジウムセリウム合金 / 内部圧力効果
Research Abstract

The physical anomalies of Pd_7Ce, L-Pd_5Ce and Pd_3Ce alloys were studied by means of X-ray powder diffraction, electron microscopy, electrical resistivity measurement at low temperatures (10-300 K) and L_3-XANES (X-ray absorption near edge structure). Special attention was paid to the relationship of the physical anomalies with the state of atomic ordering in the alloys. The following results were obtained.
1. The degree of order in the Pd-Ce alloys decreases with annealing temperature and with the degree of off-stoichiometry. The changes in the degree of order are associated with small changes in the atomic volume in the alloys. The small change in atomic volume, however, has no significant effect on the valence of Ce.
2. In Pd_7Ce and L-Pd_5Ce, the electrical resistivity at room temperature and the temperature coefficient of the resistivity show a strong dependence upon the annealing temperature. This suggests that the decrease in the degree of order enhances the concentrated Kondo effect (scatterings of conduction electrons by isolated spins of 4f electrons in Ce) of the alloys.
3. For Pd_3Ce, the electrical resistivity is almost independent of annealing temperature, except for the absolute value of resistivity at room temperature for the alloy with the stoichiometric composition.
From these experimental results, the effects of stomic disordering on the valence fluctuation were discussed in terms of the changes in atomic volume and in the configurations of Ce in the alloys. In the latter, the correlation between the configurations of Ce atoms and of Ce^<3+> was taken into account.

Report

(3 results)
  • 1990 Annual Research Report   Final Research Report Summary
  • 1989 Annual Research Report
  • Research Products

    (19 results)

All Other

All Publications (19 results)

  • [Publications] 桑野 範之: "L_3ーXANES解析によるCeの中間価数の測定" 九州大学総合理工学研究科報告. 11. 195-200 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masaru ITAKURA: "Composition and Temperature Dependence of Antiphase Domain Size of Long Period Superstructures in LーPd_5Ce" Jounal of Electron Microscopy. 39. 1-6 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Noriyuki KUWANO: "LongーPeriod Modulated Structures in Pdー12.5 at%Ce and Pdー15 at%Ce Alloys" XIIth Inter.Cong.Electron Microsc.,Seattle,WA,U.S.A.4. 164-165 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masaru ITAKURA: "Formation Process of Periodic NonーConservative Antiphase Boundary Structure in LーPd_5Ce" XIIth Inter.Cong.Electron Microsc.,Seattle,WA,U.S.A.4. 162-163 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] 梅尾 和則: "高圧下におけるPdCe金属間化合物相の電気抵抗異常" 九州大学中央分析センタ-報告. 8. 29-36 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Kensuke OKI: "Intermediate Valences of Ce and Electrical Resistivity Changes of PdーCe Intermetallic Compounds" Journal of Applied Physics. 69. (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Noriyuki KUWANO et al.: "Measurement of Mixed Valences of Ce by L_3-XANES Analysis" Engineering Sciences Reports, Kyusyu University. Vol. 11, No. 2. 195-200 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masaru ITAKURA et al.: "Composition and Temperature Dependence of Antiphase Domain Size of Long-Period Superstructures in L-Pd_5Ce" J. Electron Microscopy. Vol. 39. NO. 1, 1-6 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Noeiyuki KUWANO et al.: "Long-Period Modulated Structures in Pd-12.5 at%Ce and Pd-15 at%Ce" XII th Inter. Cong. Electron Microscopy, Seattle, WA, U. S. A.Vol. 4. 164-165 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masaru ITAKURA et al.: "Formation Process of Periodic Non-Conservative Antiphase Boundary Structure in L-Pd_5Ce" XII th Inter. Cong. Electron Microscopy, Seattle, WA, U. S. A.Vol. 4. 162-163 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Kasunori UMEO et al.: "Anomaly in Electrical Resistivity of PdCe Intermetallic Compound under High Pressure" Report of the Center of Advanced Instructional Analysis, Kyushu University. No. 8. 29-36 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Kensuke OKI et al.: "Intermediate Valences of Ce and Electrical Resistivity Changes of Pd-Ce Intermetallic Compounds" J. Applied Physics. Vol. 69. (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masaru ITAKURA: "Composition and Temperature Dependence of Antiphase Domain Size of Long Period Superstructures in LーPd_5Ce" Journal of Electron Microscopy. 39. 1-6 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] Noriyuki KUWANO: "LongーPeriod Modulated Structure in Pdー12.5 at%Ce and Pdー15.0 at%Ce alloys" XIIth Inter.Cong.Electon Microsc.,Seattle,WA,U.S.A.4. 164-165 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] Masaru ITAKURA: "Formation Process of Periodic NonーConservative Antiphase Boundary Structure in LーPd_5Ce" XIIth Inter.Cong.Electron Microsc.,Seattle,WA,U.S.A.4. 162-163 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] 梅尾 和則: "高圧下におけるPdCe金属間化合物相の電気抵抗異常" 九州大学中央分析センタ-報告. 8. 29-36 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] Kensuke OKI: "Intermediate Valences of Ce and Electrical Resistivity Changes of PdーCa Intermetallic Compounds" Journal of Applied Physics. 69. (1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] 桑野範之: "L_3-XANES解析によるCeの中間価数の測定" 九州大学総合理工学研究科報告. 11. 195-200 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Masaru ITAKURA(板倉賢): "Compositional and Temperatural Dependence of Antiphase Domain Size of Long Period Superstructures in L-Pd_5Ce" Journal of Electron Microscopy. 39. (1990)

    • Related Report
      1989 Annual Research Report

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Published: 1989-04-01   Modified: 2016-04-21  

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