Elecronic critical phenomena under microgravity and gravity circumstances

在本科学计划中，研究了微重力条件下和重力条件下液态合金临界混合的两相分离（TPS），特别关注临界现象中的电子性质。在地面实验室研究了液态Hg-Ga、Cd-Ga和Bi-Ga合金的电阻率R。电阻率R的浓度依赖性即使在临界浓度（CC）附近也呈现单调变化。液态Bi-Ga和Cd-Ga合金的电阻率温度系数（TCR）在CC附近表现为最大行为，液态Hg-Ga合金表现为最小行为。液态Bi-Ga合金TCR的浓度依赖性在微重力下的CC下表现出更大的最大值，这是由日本空间航天科学研究所（ISAS）发射的S520-19火箭作为ELM项目实现的。这些行为可以用临界点附近浓度波动的增长程度来解释。此外，还从R在冷却过程中的行为中提取了均匀液体（HL）的过冷行为。在微重力条件下，Bi-Ga在HL范围内的过冷程度远远大于重力条件下的过冷程度。微重力条件为研究过冷和旋流行为提供了理想的环境。

In this science plan the two phase separation (TPS) for liquid alloys with critical mixing was investigated both under microgravity condition and under gravity condition with particular interest in the electronic properties in the critical phenomena. The electricl resistivity, R,was studied for liquid Hg-Ga, Cd-Ga and Bi-Ga alloys in a laboratory on the ground. The concentration dependence of resistivity, R,show a monotonous variation even around the critical concentration (CC). However, the temperature coefficients of resistivity (TCR) around CC show maximum behaviors for liquid Bi-Ga and Cd-Ga alloys and a minimum behavior for liquid Hg-Ga alloys. The concentration dependence of measured TCR for liquid Bi-Ga alloys shows a far larger maximum behavior at CC under microgravity, which was realized as the ELM project by the launch of S520-19 rocket belonging to the Institute of Space and Astronautical Science (ISAS) in Japan. These behaviors are explained by the degree of growth of concentration fluctuations near the critical point (CP). In addition to these, the supercooling behavior of homogeneous liquid (HL) was extracted from the behavior of R on cooling process. The degree of supercooling for Bi-Ga in the HL range was far larger under microgravity than under gravity conditions. The microgravity condition provides an ideal circumstance for the study of supercooling and spinodal behaviors.