Diffusion measurements in the cubic high temperature modifications of LiNaSO 4 and LiAgSO 4

The diffusion coefficients ( D) of Li +, Na + , Ag +, K +, Tl +, Mg 2+, Ca 2+, Cd 2+, and Pb 2+ in b.c.c. LiNaSO 4 Na + in b.c.c. LiAgSO 4 have been measured as a function of the temperature. For the univalent cations, D decreases when the ionic radius increases, but for the divalent ions there is an increase in D. No mass dependence of D has been found. The results are compared with previously obtained diffusion coefficients in Li 2SO 4 and LiAgSO 4 . In LiNasO 4 the diffusion coefficients for Li and Na are equal, which is also the case for Li and Ag in LiAgso 4. However DAg is considerably lower than DLi and DNa in LiNaSO 4 and DNa lower than DLi and DAg in LiAgSO 4