Critical electronic phenomena in liquid alloys with miscibility gap

具有混溶间隙的液态合金中的关键电子现象

基本信息

批准号：
04640427
负责人：
ITAMI Toshio
金额：
$ 1.41万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

Behaviors of conduction electrons were investigated near the critical point of two liquid phase separation in liquid Bi-Ga alloys. The resistivity, rho, of liquid Bi-Ga alloys decreases moderately with the decrease of temperature, T,far above the ctitical temperature, T_c. However, with the approach to T_c the rho decreases abruptly particularly in the supercooling temperature range of homogeneous liquid, that is in the T range below the binodal line. This is considered to reflect the growth of concentration fluctuations up to the onset of the two phase separations. In addition it is to be noted that the T range of this supercooling is minimum at the critical composition X_c and larger around X_c. This indicates that the onset of two phase separations may be initiated by the spinodal decomposition. Based on these experimental facts the rho of liquid Bi-Ga alloys were investigsated under the microgravity, which was realized by the launch of rocket. It was found that under the micrograviuty, the decrease of rho on cooling process begins at 15K higher temperature than the the binodal temperature. This indicates that the microgravity condition is very effective to surpress the convection effects on the growth process of concentration fluctuations and provides the appropriate experimental circumstances for the study of true feature of two liquid phase separations. In addition it was found that the degree of supercooling is far larger under microgravity than under 1 g condition. This also indicates that microgravity conditions are very effective to study the supercooling or non equilibrium properties.

在液态BI-GA合金中，研究了传导电子的行为。液体BI-GA合金的电阻率随着温度降低（远高于临时温度，T_C）的降低而降低。但是，使用T_C的方法，RHO突然降低了，尤其是在均匀液体的超冷温度范围内，该温度范围在二线线以下的T范围内。这被认为反映了浓度波动的增长，直到两相分离的开始。此外，要注意，此超冷的T范围在关键组成X_C和X_C周围更大。这表明两个相分离的开始可能是由旋缺骨分解引发的。基于这些实验事实，在微重力下研究了液体BI-GA合金的Rho，这是通过火箭发射实现的。已经发现，在微晶，冷却过程中RHO的降低在15k的温度下开始于比二氧化体温度高15k。这表明微重力条件非常有效地旋转对流对浓度波动的生长过程的影响，并为研究两个液相分离的真实特征提供了适当的实验环境。此外，发现在微博中，超冷的程度远大于1 g条件下。这也表明微重力条件非常有效地研究超冷或非平衡特性。