It was found that the diffusivity, as a function of temperature, could be described by:

log [D (cm2/s)] = -1.35 - 2923/T(K)

The associated activation energy was 0.6eV. The corresponding diffusivity at 298K was 8.0 x 10-12cm2/s.

V.N.Chebotin, E.A.Vasilkovskaya: Elektrokhimiya, 1981, 17[12], 1910-2