The migration of Mg in monocrystals was measured, at various temperatures and partial

pressures, by depositing a thin film of the diffusant, by annealing, and by using secondary ion mass spectrometry or X-ray spectrometry to monitor the diffusion profiles. It was found that the results (table 154) could be described by the expression:

D (cm2/s) = 1.45 x 10-2PO2 (atm)0.172 exp[-2.58(eV)/kT]

By further analyzing the data, some insight into the impurity/vacancy interactions was obtained. This suggested that Mg interacted quite strongly with VNi" during exchange jumps, but hardly interacted at all when it was in a stable position.

H.Boussetta, N.Tabet, C.Monty: Journal de Physique III, 1992, 2[10], 1845-71

Table 155

Ni Grain-Boundary Diffusion in NiO