Nonstoichiometric KY(WO4)(2): crystal growth, chemical and physical characterization

KY(WO4)(2) single crystals were grown by the Bridgman-Stockbarger method. D ue to the existence of two polymorphic forms the elaboration was performed below the transition line using different fluxes chosen in the WO3-Y2O3-K2O ternary system. The compound is not stoichiometric and the crystal composi tion depends on the flux. We verified that these differences of composition did not alter the structure and the spectroscopic properties. A structure study was also performed on single crystals and powder in order to check re cent observations about the validity of the proposed structure. (C) 2000 El sevier Science B.V. All rights reserved.