The diffusivity of 86Rb ions was measured in molten samples by using the capillary reservoir method. It was found that the data, for temperatures ranging from 655 to 818C, could be described by:

D (cm2/s) = 2.06 x 10-3 exp[-6.74(kcal/mol)/RT]

T.Ejima, T.Yamamura, Y.Arita, K.Matsui: Journal of the Japan Institute of Metals, 1975, 39[4], 409-13