EXPLORING TELLURIDES - SYNTHESIS AND CHARACTERIZATION OF NEW BINARY, TERNARY, AND QUATERNARY COMPOUNDS

A fast-growing interest in solid state telluride chemistry has taken place during the past several years. Our research in this area has been primarily on the development and applications of several synthetic techniques that can be applied to the synthesis of the tellurides over a wide temperature range (100-1200 degrees C). These techniques include chemical vapor transport, molten-salt, and hydro(solvo)thermal methods. In this article, we report five binary, ternary, and quaternary metal tellurides, BaTe2, TaCu3 Te-4, RbTaCu2Te4, K2BaSnTe4, and K2Ag2SnTe4, synthesized by the molten-salt (alkali-metal polytelluride flux) reactions at intermediate temperatures (400-550 degrees C). The crystal structures of these compounds have been determined by single crystal X-ray diffraction techniques. Crystal data: BaTe2, space group I4/mcm (No. 140), a = 7.181(1), c = 8.898(2) Angstrom, Z = 4, R1 = 1.55%, wR2 = 3.46%; RbTaCu2Te4, space group P2(1)cn (No. 33), a = 5.982(2), b = 20.316(3), c = 8.192(2) Angstrom, Z = 4, R1 = 7.13%, wR2 4.95%; TaCu3Te4, space group P-43m (No. 215), a = 5.930(2) Angstrom, Z = 1, R1 = 2.40%, wR2 = 6.48%; K2BaSnTe4, space group I-43m (No. 217), a = 8.393(1) Angstrom, Z = 2, R1 = 2.52%, wR2 = 3.56%; K2Ag2SnTe4, space group I-42m (No. 121), a = 8.732(5), c = 7.425(3) Angstrom, Z = 2, R1 = 3.06%, wR2 = 7.25%. (C) 1995 Academic Press, Inc.