Crystal structure and ionic conductivity of a new bismuth tungstate, Bi3W2O10·5

The compound Bi3W2O10.5 was synthesized by the solid-state technique from Bi2O3 and WO3 in stoichiometric quantities. Single crystals were grown by the melt-cooling technique and the crystal structure was solved in the tetragonalI4/m space group witha = 3.839 (1) A,c = 16.382 (5) A,V = 241.4 (1) A3,Z = 4 and was refined to anR index of 0.0672. The structure represents a modification of the Aurivillius phase and consists of [Bi2O2]2+ units separated by WO8 polyhedra. a.c. impedance studies indicate oxide ion conductivity of 2.91 10−5 Scm−1 at 600°C.