Crystal structure and phase transitions of Sr2CdWO6.

Abstract

The crystal structure of Sr2CdWO6, prepared by solid state reaction, was determined by high-resolution X-ray diffraction at different temperatures. At room temperature, this compound has a monoclinic structure (space group P2(1)/n) with a = 5.7463(1), b = 5.8189(1), c = 8.1465(1), β = 90.071(1). At 1105 K the structure is converted to tetragonal (space group I4/m). Diffraction data also suggest that a cubic phase exists above 1220K. Comparing the phase transition temperatures of Sr2CdWO6 with those of other compounds of the Sr2MWO6 family reported previously, it was observed that the transition temperatures are higher in compounds with low-tolerance factors. At the same time, the temperature range in which the intermediate tetragonal phase exists is reduced. © 2007, Elsevier Ltd.