The behavior of Ni in monocrystalline material was investigated at 613 to 949K. Ion-beam sputtering and secondary-ion mass spectrometry were used to measure the concentration versus depth profiles. It was found that the diffusion of Ni could be described by:

D(cm2/s) = 6.2 x 10-1exp[-2.32(eV)/kT]

It was noted that these results were consistent with previously reported high-temperature tracer data. By combining the latter data with the present low-temperature results, a curvature of the Arrhenius plot was revealed. This curvature was attributed to the contribution that was made by di-vacancies at high temperatures.

A.Almazouzi, M.P.Macht, V.Naundorf, G.Neumann: Physical Review B, 1996, 54[2], 857-63