The migration of small homovalent cations in the monocrystalline material was studied by using tracer/sectioning methods. It was found that the results could be described by the expression:

D (cm2/s) = 19 exp[-35.59(kcal/mol)/RT]

It was concluded that the diffusion behavior of the cations was in good agreement with the so-called displaced homovalent small-radius cation model.

S.M.Klotsman, I.P.Polikarpova, G.N.Tatarinova, A.N.Timofeev: Physical Review B, 1988, 38[11], 7765-76