Diffusivities were measured in single crystals as a function of temperature under O partial pressures of between 0.0001 and 0.21atm, and as a function of partial pressure at 1245C. It was found that the results could be described by the relationship:

D(cm2/s) = 0.23 PO20.117 exp[-3.18(eV/atom)/kT]

The data were analyzed by using 3 models for the point defect population, and this permitted a detailed interpretation to be made of Ca/vacancy interactions. It was shown that the contribution made by VNi’ was negligible, and that VNi” interacted closely with Ca during exchange jumps.

H.Boussetta, M.Labidi, C.Dolin, C.Monty: Journal de Physique III, 1995, 5[11], 1759-70