The critical behaviour under microgravity of liquid alloys with mutual immiscibility

Abstract

The process of two-liquid phase separation (TLPS) was studied by the electrical resistivity, ρ, both on the ground and under microgravity obtained on board the sounding rocket. On cooling to the critical temperature, Tc, on the ground, increase of ρ and decrease of the temperature coefficient of ρ, dρ/dT were found in the homogeneous liquid phase of liquid Bi–Ga and Cd–Ga alloys. However, increase of ρ and decrease of dρ/dT were observed for the liquid Hg–Ga system. Both tendencies were explained successfully by the concentration fluctuation model. The rocket experiment for the ρ of liquid Bi–Ga alloys revealed that, under microgravity, the concentration fluctuation grows extensively and the nucleation for TLPS is suppressed.