STRUCTURE AND THERMODYNAMIC PROPERTIES OF LIQUID BI-GA ALLOYS WITH MISCIBILITY GAP

Neutron diffraction, ultrasonic velocity and density measurements have been carried out for liquid Bi-Ga alloys along the liquidus curve and at temperatures above the critical point where the miscibility gap closes. A remarkable change in the structure factor has been observed at the critical concentration around 70 at.% Ga. The adiabatic compressibility of this system obtained from the sound velocity and density shows an almost linear concentration dependence. The temperature dependence of the adiabatic compressibility is weaker in the concentration region corresponding to the miscibility gap than at other compositions. The concentration variation of the structure factor is discussed from the point of view of the thermodynamic properties of this system.