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1995 Fiscal Year Final Research Report Summary

Theoretical Investigations of Structure vs Magnetism in Amorphous Alloys Showing Anomalous Magnetic Behaviors

Research Project

Project/Area Number 05640428
Research Category

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

Allocation TypeSingle-year Grants
Research Field 固体物性Ⅱ(磁性・金属・低温)
Research InstitutionHokkaido Institute of Technology

Principal Investigator

KAKEHASHI Yoshiro  Division of General Educations, Hokkaido Institute of Technology, Professor, 教養部, 教授 (10191975)

Co-Investigator(Kenkyū-buntansha) UCHIDA Takashi  Division of General Educations, Hokkaido Institute of Technology, Lecturer, 教養部, 講師 (90265059)
Project Period (FY) 1993 – 1995
Keywordsamorphous alloys / metallic magnetism / itinerant magnetism / transition-metal alloys
Research Abstract

We have developed a finite-temperature theory of amorphous magnetic alloys on the basis of the functional integral method, combining the distribution function method describing random distribution of local magnetic moments with the geometrical-mean model for electronic structure calculations in amorphous alloys. applying our theory to amorphous Fe-Zr alloys whose ferromagnetism is destroyed by structural disorder, and amorphous Co-Y alloys with ferromagnetism enhanced by the structural disorder, we clarified the effects of structural disorder on their electronic structures and various magnetic properties. Next, we applied the theory to amorphous TM-Y (TM=Mn, Fe, Co, Ni) alloys showing peculiar magnetism, and showed that the most random atomic configuration explains the over-all features of their magnetic phase diagrams such as the appearance of spin glass (SG) in Mn-Y,the SG-F (ferromagnetism)-P (paramagnetism) transition in melt-spun Fe-Y,and the F-P transition in Co-Y and Ni-Y alloys … More . The theory also explained the concentration and temperature dependences of magnetizations and susceptibilities, semi-quantitatively. These magnetism is caused by the antiferromagnetic couplings between Mn local moments (Mn-Y), the local environment effects of magnetic moments and the nonlinear magnetic coupling between Fe local moments (Fe-Y), the atomic-size effects (Fe-Y and Co-Y), and 3d-4d hybridization (Co-Y and Ni-Y). We also examined the effects of atomic short range order in Fe-Y,and found that the F-SG transition occurs with increasing Fe-Fe pairs because of the increasing coordination number of Fe via atomic-size effects and the nonlinear magnetic coupling. This gives a mechanism for the single-phase SG in sputtered Fe-Y amorphous alloys. Finally, we proposed a theory which interpolates between crystal and amorphous structure. The application to Fe led to the conclusion that the ferromagnetism of bcc Fe becomes unstable when the fluctuation of interatomic distance (DELTA) becomes more than 0.05 along the bcc-amorphous line. In the case of Ni, we showed that the Curie temperature is rapidly decreased by increasing DELTA along the fcc-amorphous line. Less

  • Research Products

    (42 results)

All Other

All Publications (42 results)

  • [Publications] M. Yu: "Strong Ferromagnetism in Amorphous Fe-Ni Alloys" in “Physics of Transition Metals" ed by P.M.Oppeneer and J.Kubler(World Sci.Pub.,Singapore). 930-933 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi.: "Anomalous Magnetic Behaviors of Re-entrant Spin Glasses in Amorphous Transition Metals." in “Physics of Transition Metals" ed by P.M.Oppeneer and J. Kubler(World Sci. Pub.,Singapore). 993-996 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "A Single-Site Theory of Magnetism in Amorphous Fe-Ni Alloys." J.Appl. Phys.73. 3426-3432 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "A Simple Theory of Electronic-Structure Calcu-lations in Amorphous Transition-Metal Alloys." Phys. Rev.B. 47. 7736-7746 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 梯 祥郎: "磁性金属のバンド理論" 日本応用磁気学会誌. 17. 714-721 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "Finite-Temperature Theory of Amorphous Magnetic Alloys." Phys. Rev.B. 49. 352-367 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Magnetism of Amorphous Transition Metals and Alloys." Mater.Sci. & Engi.A. 179-180. 62-65 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Enhancement of Curie Temperature in Amorphous Co-Y Alloys." Mater.Sci. & Engi.A. 181-182. 946-949 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "Ferromagnetism and Spin Glass in Amorphous Fe-Zr Alloys." Mater.Sci. & Engi.A. 181-182. 856-859 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Metallic Magnetism in Amorphous Co-Y Alloys" Phys. Rev.B. 49. 15076-15083 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "Existence of the Spin-Glass State in Amorphous Fe." Phys. Rev.B. 49. 15723-15729 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Theory of Amorphous Metallic Magnetism with Self-consistent Amplitude Fluctuations and Its Application to Amorphous Fe." Phys. Rev.B. 50. 6189-6198 (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Improved Theory of Amorphous Metallic Magnatism and Application to Amorphous Fe." J.Magn.Magn.Mater.140-144. 255-256 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Theoretical Investigations of Magnetism in Amorphous TM-Y (TM=Mn,Fe,Co,Ni) Alloys." J.Magn.Magn.Mater.140-144. 263-264 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "T-V Magnetic Phase Diagram of Amorphous Fe." J.Magn.Magn.Mater. 140-144. 279-280 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "Spin Glass and Ferromagnetism in Amorphous Fe-M (M=Zr,Y) Alloys." J.Magn.Magn.Mater.140-144. 289-290 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "Theory of Magnetism in Amorphous Fe-Zr Alloys." J.Magm.Magn.Mater.155 (to be published). (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu: "Finite-Temperature Magnetism in Amorphous Fe-Y Alloys." J.Phys.Condensed Matter. (to be published).

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "Metallic Magnetism in Amorphous TM-Y (TM=Mn,Fe,Co,Ni) Alloys." Zeitschrift fur Physik B. (to be published).

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Kakehashi: "The Magneism of Amorphous Matals and Alloys" World Sci.Pub., 334 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yu, Y.Kakehashi: "Strong Ferromagnetism in Amorphous Fe-Ni alloys" Physics of Transition Metals ed by P.M.Oppeneer and J.Kubler (World Sci.Pub., Singapore, 1993). 930-933

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi: "Anomalous Magnetic Behaviors of Re-entrant Spin Glasses in Amorphous Transition Metals" Physics of Transition Metals ed by P.M.Oppeneer and J.Kubler (World Sci.Pub., Singapore, 1993). 993-996

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "A Single-Site Theory of Magnetism in Amorphous Fe-Ni Alloys" J.Appl.Phys.73 (7). 3426-3432 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, H.Tanaka, M.Yu: "A Simple Theory of Electronic-Structure Calculations in Amorphous Transition-Metal Alloys" Phys.Rev.B. 47. 7736-7746 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, M.Yu, H.Tanaka: "Band Theory in Magnetic Metals and Alloys" J.Appl.Magnetics. 17, No.4. 714-721 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi, H.Tanaka: "Finite-Temperature Theory of Amorphous Magnetic Alloys" Phys.Rev.B. 49. 352-367 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi: "Magnetism of Amorphous Transition Metals and Alloys" Mater.Sci.& Engi.A179-180 (Proceedings RQ8). 62-65 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi: "Enhancement of Curie Temperature in Amorphous Co-Y Alloys" Mater.Sci.& Engi.A181-182 (Proceedings RQ8). 946-949 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "Ferromagnetism and Spin Glass in Amorphous Fe-Zr Alloys" Mater.Sci.& Engi.A181-182 (Proceedings RQ8). 856-859 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, M.Yu: "Metallic Magnetism in Amorphous Co-Y Alloys" Phys.Rev.B49. 15076-15083 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "Existence of the Spin-Glass State in Amorphous Fe" Phys.Rev.B49. 15723-15729 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, M.Yu: "Theory of Amorphous Metallic Magnetism with Self-consistent Amplitude Fluctuations and Its Application to Amorphous Fe" Phys.Rev.B50. 6189-6198 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi: "Magnetism and Electronic Structure in Disordered Systems" Application of Theory of Electron in Solids" (ISBN 4-88903-103-0, Japan Institute of Metals, 1994). 87-95

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi , M.Yu, T.Uchida: "Theory of Metallic Magnetism from Crystals to Amorphous Structure" J.Magn.Magn.Mater.140-144 (Proceedings ICM'94). 251-252 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, M.Yu: "Improved Theory of Amorphous Metallic Magnetism and Application to Amorphous Fe" J.Magn.Magn.Mater.140-144 (Proceedings ICM'94). 255-256 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi , M.Yu: "Theoretical Investigations of Magnetism in Amorphous TM-Y (TM=Mn, Fe, Co, Ni) Alloys" J.Magn.Magn.Mater.140-144 (Proceedings ICM'94). 263-264 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "T-V Magnetic Phase Diagram of Amorphous Fe" J.Magn.Magn.Mater.140-144 (Proceedings ICM'94). 279-280 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "Spin Glass and Ferromagnetism in Amorphous Fe-M (M=Zr, Y) Alloys" J.Magn.Magn.Mater.140-144 (Proceedings ICM'94). 289-290 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, H.Tanaka: "Theory of Magnetism in Amorphous Transition Metals and Alloys" The Magnetism of Amorphous Metals and Alloys, ed.by J.A.Fernandez-Baca and W.Y.Ching (ISBN 981-02-1033-7 World Sci.Pub., Singapore, 1995). vspace0.3cm. 1-84

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "Theory of Magnetism in Amorphous Fe-Zr Alloys" J.Magn.Mang.Mater.(to be published).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Yu, Y.Kakehashi: "Finite-Temperature Magnetism in Amorphous Fe-Y Alloys" J.Phys.Condensed Matter. (to be published).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kakehashi, M.Yu: "Metallic Magnetism in Amorphous TM-Y (TM=Mn, Fe, Co, Ni) Alloys" Zeitschrift fur Physik B. (to be published).

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1997-03-04  

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