Oxygen self-diffusion in cerium oxide

Abstract

Polycrystalline cerium oxide was prepared by sintering and used for oxygen diffusion experiments by the gas phase analysis. Lattice constant measurements confirmed the stoichiometric condition of the sample. Although Si was contained in the specimens as an impurity, it was considered that point defects were not created by Si, because both Siand Ce have the same valence. The oxygen diffusion coefficient obtained in the present work could be represented by the equation: Doxy=0.364 exp(-322 kJ·mol-1/RT)m2·s-1. This result is similar to the oxygen self-diffusion coefficients in other stoichiometric oxides with fluorite structure. This agreement with literature values was considered to be a confirmation that the diffusion coefficient obtained in this work is actually that of oxygen in a stoichiometric CeO2 lattice.