The interdiffusion between NiO and CoO-doped MgO was investigated by using a solid-state galvanic cell method at temperatures ranging from 1273 to 1439K. The extraction of interdiffusivity data from the cell results required a knowledge of the activity of NiO in the CoO-MgO-NiO system. The thermodynamics of this system were deduced from published data, on the various binary systems, by using a 2-sublattice model. The final results indicated that, at low dopant concentrations, the variation in the interdiffusivity was insignificant. However, when 10mol%CoO in a CoO-MgO solid solution was put in contact with 50mol%NiO, there was an increase in the diffusion rate.

P.Zhang: Solid State Ionics, 1996, 89[3-4], 241-54