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Production of Quasicrystalline Alloys, Their Structures and Physical Properties

准晶合金的生产、其结构和物理性能

基本信息

批准号：
61460029
负责人：
TAKEUCHI Shin
金额：
$ 4.99万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

The purpose of the research in to produce high-quality quasicrystalline alloys and to investigate physical properties characteristic of quasicrystals.(1) Production of high-quality quasicrystals (a) Al-Mn based alloys: We have first determined the composition range of Al-Mn bianry alloys in which single-quasicrystalline phase is produced by melt-quenching. Then we have clarified the composition region of the quasicrystalline phase for ternary Al-Mn-Si system and further tried to improve the quality by subsitution of 14 transition elements for Mn. As a result, we have succeed in obtaining excellent-quality and very stable quasicrystalline phase for some quaternary systems such as Al-Ru-Mn-Si. (b) Simple Metal systems: We have also determined the composition region of single-quasicrystalline phase for the ternary Mg-Al-Zn systems. We have also produced large grain quasicrystals of Al-Li-Cu alloy.(2) Electrical resistivities of quasicrystals We have measured the electrical resistivity and the magnetic susceptivility for the produced single-phase quasicrystalline alloys. the resistivities of Al-Mn systems are as high as the order of 1 m cm and have a negative temperature coefficent. Below about 50K, we observed an anomalous resistivity increase, the amount of which has been found to be closely related to the localized magnetic moment of Mn. The magneto-resistance is negative in the -logT-dependent region, in contradictory with the Kondo effect. This resisitivity anomaly has been tentatively interpreted by the critical state of electrons in the quasicrystalline state. Systematic measurements for simple-metal quasicrystals such as Mg-Al-Zn and Al-Li-Cu are in progress.

本研究的目的是生产高质量的准晶合金，并研究准晶的物理特性。(1)高质量准晶的生产(a) Al-Mn基合金：我们首先确定了Al-Mn双晶合金的成分范围，其中单准晶是通过熔体淬火产生的。在此基础上，明确了Al-Mn-Si三元体系准晶相的组成区域，并进一步尝试用14种过渡元素取代Mn来改善其质量。结果表明，我们成功地获得了Al-Ru-Mn-Si等四元体系中质量优异且非常稳定的准晶相。(b)简单金属体系：我们还确定了三元Mg-Al-Zn体系的单准晶相组成区域。我们还生产了大晶粒准晶的铝锂铜合金。测定了制备的单相准晶合金的电阻率和磁化率。Al-Mn体系的电阻率高达1 m cm数量级，且具有负温度系数。在约50K以下，我们观察到电阻率的异常增加，其幅度与Mn的局域磁矩密切相关。磁电阻在- logt依赖区域为负，与近藤效应相矛盾。这种电阻率异常已初步用准晶态中电子的临界态来解释。对简单金属准晶体如Mg-Al-Zn和Al-Li-Cu的系统测量正在进行中。