Lattice parameter, defect concentration and oxygen diffusion in ceria solid solutions

Abstract

The results of x-ray diffraction, the size of lattice parameter, and the values of oxygen diffusion coefficient in YO_1.5-CeO₂, GdO_1.5-CeO₂, and NdO_1.5-CeO₂ systems were reviewed. In YO_1.5-CeO₂ system, the lattice parameter decreases as the concentration of YO_1.5 increases. In GdO_1.5-CeO₂ system, the lattice parameter does not change very much. And in NdO_1.5-CeO₂ system, it increases as the concentration of NdO_1.5 increases. When the oxygen diffusion coefficient was plotted as a function of lattice parameter, there was no correlation between them. However, when the oxygen diffusion coefficient was plotted as a function of the concentration of trivalent cation additives, there was very good correlation between them. Consequently, the diffusion coefficient does not depend on the size of crystal lattice in ceria solid solutions, but it depends on the concentration of trivalent cation additives.