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Experimental and Theoretical Research for Electrical Properties of Quasicrystals

准晶体电学性质的实验与理论研究

基本信息

批准号：
07455254
负责人：
INO Hiromitsu
金额：
$ 4.35万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

The formation range of single icosahedral phase in the Al-Pd-Re system has been extensively studied based on a large variety of alloys with slitely different compositions. Composition dependence of electrical resistivity was successfully obtained for the first time in the Al-Pd-Re system. In order to elucidate the origin of the composition dependence of resistivity, the quasilattice constant and the intensities of the 1/2(311111)superlattice peak and the(211111)five fold peak have been closely investigated and it has been found that an increase of the quasilattice constant and deviation from closely packed structures coincide with an increase of the resistivity of alloys. Measurements of the temperature dependences of the resistivity, Hall coefficient and magnetoresistance on samples with different compositions and different resistivity values have been presented to shed light on the conduction mechanism in the insulating Al-Pd-Re quasicrystal. Discussions on the conduction mechanism are presented in terms of the band scheme. An analysis on the temperature dependence of conductivity and Hall coefficient in high temperature region(>20K)are performed based on the two band model which takes account of the temperature variation of the effective electrons and holes. The conductivity and magnetoresistance data in low temperature region(<20K)are analyzed in the framework of the weak localization and the electron-electron interaction theories.

Al-Pd-Re系中单一二十面体相的形成范围已被广泛地研究过，其基础是大量的具有细微不同成分的合金。首次在Al-Pd-Re体系中成功地获得了电阻率的组分依赖性。为了阐明电阻率与组成的关系，我们仔细研究了准晶格常数、1/2（311111）超晶格峰和（211111）五重峰的强度，发现准晶格常数的增加和偏离紧密堆积结构与合金电阻率的增加相一致。测量了不同组分和不同电阻率的Al-Pd-Re准晶样品的电阻率、霍尔系数和磁阻随温度的变化关系，以揭示绝缘Al-Pd-Re准晶的导电机理。讨论的传导机制的能带计划。基于考虑有效电子和空穴温度变化的双带模型，分析了高温区（> 20 K）电导率和霍尔系数的温度依赖性。在弱局域化和电子-电子相互作用理论的框架下，分析了低温区（<20 K）的电导和磁阻数据。