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

log [D (cm2/s)] = -1.89 - 2698/T(K)

The associated activation energy was 0.5eV. The corresponding diffusivity at 298K was 1.2 x 10-11cm2/s. V.N.Chebotin, E.A.Vasilkovskaya: Elektrokhimiya, 1981, 17[12], 1910-2