2012 Volume 20thAnniv Pages 59-63
The results of x-ray diffraction, the size of lattice parameter, and the values of oxygen diffusion coefficient in YO1.5-CeO2, GdO1.5-CeO2, and NdO1.5-CeO2 systems were reviewed. In YO1.5-CeO2 system, the lattice parameter decreases as the concentration of YO1.5 increases. In GdO1.5-CeO2 system, the lattice parameter does not change very much. And in NdO1.5-CeO2 system, it increases as the concentration of NdO1.5 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.