Growth of fluctuations under microgravity in liquid Bi-Ga alloys

The first measurement under microgravity of electrical resistivity ρ (or resistance R) was performed for a liquid Bi-Ga system during a parabolic rocket flight. Specially designed Ti cells were used. The real time data of ρ (or R) were obtained on earth during a cooling process from the homogeneous liquid phase (HLP) to the two-liquid phase (TLP) by means of telemetry. The ρ decreases moderately, and its temperature coefficient, (dρ/dT)/ρ, increases abruptly with the approach to binodal temperatures in a cooling process from HLP to TLP, particularly for liquid alloys near the critical concentration. The (dρ/dT)/ρ shows a maximum at the critical composition. This decreasing tendency of p continues even in supercooled states of HLP up to the onset of TLP separation. The supercooling under microgravity is distinctly larger than that obtained under gravity on earth.