Lattice parameter and density of cerium oxide doped with gadolinium

Abstract

Cerium oxide doped with 0∼90 mol% GdO_1.5 was prepared by co-precipitation method, which was found to be much better method than solid state reaction method. The formation of solid solution at CeO₂ doped with 10 mol% GdO_1.5 was recognized even without firing the precipitate. X-ray diffraction study (50 kV, 200 mA) of sample fired at 1300°C revealed that fluorite structure existed in samples with 0∼35 mol% GdO_1.5. At composition with higher concentration of GdO_1.5, superlattice peaks were identified. This indicated the existence of a fluorite phase with superlattice or the formation of rare earth C-type structure. Density of sample fired at 1450 °C was measured by densitometer. The results show that structure of sample is a cation interstitial model with 10mol% GdO_1.5 and a anion vacancy model with 30∼50mol% GdO_1.5.