Experimental procedure to determine the interdiffusion coefficient of miscibility gap liquid alloys: Case of GaPb system

An experimental procedure to measure the interdiffusion coefficient of nondilute binary Ga0.6Pb0.4 liquid alloys exhibiting a miscibility gap is demonstrated. The phase separation is found to be instantaneous, while the formation of a homogeneous alloy is relatively slow. This technique is based on the measurement of the electrical resistivity of liquid alloys during the formation process in a finite capillary. The concentration profiles, deduced from the electrical resistivity data, combined with the Boltzmann-Matano method [C. Matano, Jpn. J. Phys. 8, 109 (1933)] were used to determine the concentration dependence of the interdiffusion coefficient.