Diffusion in Cubic Sulphates

Abstract

The interdiffusion coefficients (D) of Na+, Ag+, K+, Rb* and Τl+ in pure f. c. c. Li2SO4 have been measured between 590 and 820 °C. D and the Arrhenius’ activation energies decrease in the same order as the ionic radii increase. D is a function both of the masses and the radii of the impurity cations. The results show that the Na+ and Ag* ions mainly diffuse in the sulphate lattice with the same mechanism as the lithium ions, while the larger ions are mobile in defects in the lattice. The Li*, Na+ and Ag* ions are probably diffusing between octahedral positions.