Existence region diagrams for the structural types of MR(WO4)2 compounds (M = NH4, Cu, Ag, Tl; R = trivalent metal)

An additional experimental investigation has been carried out, and data on 72 MR(WO 4 ) 2 compounds are summarized. In the general formula, M stand for ammonium, copper(I), silver(I), or thallium(I); R(III) stands for La-Lu, Y, Sc; In or Bi (with Cu(I), Ag(I), Tl(I)); Ga or Cr (with Cu(I)). The compounds have been prepared by different methods and characterized by physicochemical methods. Refined diagrams of existence regions for the structural types of the compounds are constructed, and applications of these compounds are discussed.