Structure and conductivity of strontium-doped cerium orthovanadates Ce1- xSrxVO4 (0 0.175)

A-site substituted cerium orthovanadates, Ce1-xSrxVO4, were synthesised by solid-state reactions It was found that the solid solution limit in Ce1-xSrxVO4 is at x = 0 175. The crystal structure was analysed by X-ray diffraction and it exhibits a tetragonal zircon structure of space group I4(1)/amd (1 4 1) with a = 7 3670 (3) and c = 6.4894 (1) angstrom for Ce0 825Sr0 175VO4 The UV-vis absorption spectra indicated that the compounds have band gaps at room temperature in the range 4.5-4 6 eV Conductivity measurements were performed for the first time up to the strontium solid solution limit in air and in dry 5% H-2/Ar with conductivity values at 600 degrees C ranging from 03 to 30 mS cm(-1) in air to 30-45 mS cm(-1) in reduced atmosphere Sample Ce0 825Sr0 175VO4 is redox stable at a temperature below 600 degrees C although the conductivity is not high enough to be used as an electrode for solid oxide fuel cells.