The diffusion of 63Ni was measured in epitaxial thin films, deposited onto (100) SrTiO3 substrates, at temperatures ranging from 550 to 650C and under an O2 partial pressure of 1bar. The deviation from stoichiometry was between 0.3 and 0.4. It was found that the diffusion behavior could be described by:

D (cm2/s) = 1.3 exp[-2.7(eV)/kT]

These values were many orders of magnitude lower than published data for O diffusion. A diffusion mechanism which involved thermal vacancies and atomic jumps along diagonal directions of [110]-, [301]- or [031]-type was suggested to describe the long-range diffusion of cations which occupied Cu sites.

D.Gupta, R.B.Laibowitz, J.A.Lacey: Physical Review Letters, 1990, 64[22], 2675-8