Tracer Impurity Diffusion in Liquid Metals: In in Gallium and Ga in Indium

Diffusion measurements have been made for 114In in Ga between 20° and 455 °C, and for 72Ga in In between the m.p. and 380 °C. Linear plots of D vs T describe the results about equally well as Arrhenius representations. The Arrhenius parameters are D0 = 2.1 • 104 cm2/s, @ = 1.64 kcal/mol for In in Ga, D0 = 2.4 • 10~ 4 cm2/'s, Q = 1.93 kcal/mol for Ga in In. Ga diffuses faster than In in both matrices. The effective activation energy of Ga is much higher than that of In in the lighter solvent, but the opposite is the case in In. Simple electrostatic screening arguments cannot be applied to the latter results. A recent model, predicting a nearly linear temperature dependence of D, appears somewhat better applicable.