Thermal expansion of Gd-doped ceria and reduced ceria

The thermal expansion coefficients of CeO2 and Gd-doped ceria were measured in the range from 100 to 873 K and those of reduced ceria were measured fr om 100 to 323 K. The thermal expansion coefficient of Ce1-xGdxO2-x/2 became large with increasing the dopant content, x. The thermal expansion coeffic ient of reduced ceria became large with increasing the vacancy content of o xygen. These increases of the thermal expansion coefficients result from we akening binding energy due to the increase of oxygen vacancy. The thermal e xpansion coefficients of CeO2 and Gd-doped ceria were calculated theoretica lly and they were in good agreement with experimental ones except for the h igher temperature range. (C) 2000 Elsevier Science B.V. All rights reserved .