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Thermoelectric effect of quasicrystals and development of thermoelectric-device materials by controlling the psuedogap

Research Project

Project/Area Number 10554016
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section展開研究
Research Field 固体物性Ⅱ(磁性・金属・低温)
Research InstitutionNagoya University

Principal Investigator

MIZUTANI Uichiro  Nagoya Univ., Grad. School of Eng., Professor, 大学院・工学研究科, 教授 (00072679)

Co-Investigator(Kenkyū-buntansha) TAKEUCHI Tsunehiro  Nagoya Univ., Grad. School of Eng., Assistant Professor, 大学院・工学研究科, 助手 (00293655)
IKUTA Hiroshi  Nagoya Univ., CIRS., Associate Professor, 理工科学総合研究センター, 助教授 (30231129)
Project Period (FY) 1998 – 1999
Project Status Completed (Fiscal Year 1999)
Budget Amount *help
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 1999: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1998: ¥9,000,000 (Direct Cost: ¥9,000,000)
Keywordsquasicrystal / approximant / pseudogap / thermoelectric power / Seebeck coefficient / Mott theory / 熱電材料 / 熱電素子
Research Abstract

The presence of the pseudogap across the Fermi level has been regarded as one of the most characteristic features in quasicrystals and their approximates and is known to affect critically the electron transport properties. The concept of the pseudogap has been established by Mott in 1968 in his discussion of the metal-insulator transition of liquid mercury at high temperatures and high pressures. The principal investigator demonstrated the validity of the Mott theory for quasicrystals and their approximants by showing that the electrical conductivity is proportional to the square of the depth of the pseudogap and provided firm basis for the research aiming at the application of unique transport properties of quasicrystals and their approximants.
In the present project, we focused on the thermoelectric effect. The thermoelectric device is the device, which is capable of transforming heat into electricity or electricity into heat. The latter is expected to be applicable to the electronic refrigerator. We have measured the thermoelectric power in the temperature range 80-400 K and aimed at establishing the guiding principles to develop the thermoelectric device materials in the family of quasicrystals and apploximants.
In the year of Heisei 10, we purchased the thermoelectric power acquisition system by using this fund and could successfully test the machine by measuring the Seebeck coefficient of Al-Mg-Pd and Al-Mg-Zn quasicrystals.
In the year of Heisei 11, we extended the measurements to Al-Cu-Fe, Al-Cu-Fe-Si and Al-Pd-Mn systems. We revealed that both Seebeck coefficient and Hall coefficient concomitantly change the sign from a positive to negative one by varying Fe concentration in the Al-Cu-Fe system. We concluded from this that the system changes from the electron to hole states. We also revealed that the single quasicrystal Al-Mn-Pd exhibits the Seebeck coefficient of 80 μV/K, which is almost independent of the orientation of the quasicrystal.

Report

(3 results)
  • 1999 Annual Research Report   Final Research Report Summary
  • 1998 Annual Research Report
  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] U. Mizutani: "Electron Transport Mechanism in the pseudogap systems : Quasicrystals, Approximants and Amorphous Alloys"Proceedings of 7th Int. Conf. on Quasicrystals (Stuttgart, Germany). (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] T. Takeuchi, T. Mizuno, E. Banno, U. Mizutani: "Magic Number of Electrons in the Icosahedral cluster of AlxMg40x60-x(X=Zn, Pd, Ag, Cu)y1-approximants"Proceedings of 7th Int. Conf. on Quasicrystals (Stuttgart, Germany). (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] U.Mizutani: "Electron Transport Mechanism in the Pseudogap Systems : Quasicrystals, Approximants and Amorphous Alloys"Proceedings of 7th Int. Conf. on Quasicrystals (Stuttgart, Germany, September 1999). (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] T.Takeuchi, T.Mizuno, E.Banno and U.Mizutani: "Magic Number of Electrons in the Icosahedral Cluster of AlxMg40X60-x (X=Zn, Pd, Ag and Cu) 1/1-Approximants"Proceedings of 7th Int. Conf. on Quasicrystals (Stuttgart, Germany, September 1999). (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Uichiro Mizutani: "Role of the pseudogap in the electron transport of quasicrystals and their approximants"Journal of Physics: Condensed Matter. 10. 4609-4623 (1998)

    • Related Report
      1999 Annual Research Report
  • [Publications] Hiroshi Yamada: "Structural Investigation of Al_<55>Si_7Cu_<25.5>Fe_<12.5> 1/1-approximant"Materials Research Society Symposium Proceeding. 553. 117-122 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Takayuki Mizuno: "Hybridization effect on electron transport properties of Rhombic Triacontahedral-type Al_<60-x>Mg_<40>X_x (X=Zn,Cu,Ag and Pd)1/1-Cubic approximants"Materials Research Society Symposium Proceedings. 553. 359-364 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Uichiro Mizutani: "Electron transport mechanism in the pseudogap systems: quasicrystals, approximants and amorphous alloys"Proc. of 7th Int. Conf. on Quasicrystals (Stuttgart, Germany 1999). 500-504 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Tsunehiro Takeuchi: "Magic number of electron in the icosahedal cluster of Al_xMg_<60>X_<60-x> (X=Zn,Pd,Ag and Cu) 1/1-cubic approximants"Proc. of 7th Int. conf. on Quasicrystals (Stuttgart, Germeny 1999). 510-515 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Uichiro Mizutani: "Role of the pseudogap in the elictiontrenaport of qunaicryetals and their appeariments" Journal of Physics Condenced Matter. vol.10. 4609-4623 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Hiroshi Yamada: "Structural Investigation of Al55Si7Cu25.5Fe12.5→Al_<55>Si_7Cu_<25.5>Fe_<12.5> 1/1-approximant" Proc.of the Materials Research Society. vol.553(印刷中). (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] Takayuki Mizuno: "Electronic Propertion and structures of rhomlic triacontahedial approximant crystals" Proc.of the Materials Research Society. vol.553(印刷中). (1999)

    • Related Report
      1998 Annual Research Report

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Published: 1998-04-01   Modified: 2020-05-15  

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