SYNTHESIS AND CRYSTAL-STRUCTURE OF A NEW ALKALINE-EARTH METAL CHALCOGENIDE - BARIUM DITELLURIDE

During our exploration of kinetically stable solid state materials, we have discovered a new binary material, BaTe2, the first alkaline eart h metal dichalcogenide prepared using flux growth technique. The cryst al structure of BaTe2 was determined by single-crystal X-ray diffracti on methods. It belongs to the tetragonal space group I4/mcm (No. 140) with lattice constants a = 7.181(1)angstrom, c = 8.898(2)angstrom, V = 458.8(1)angstrom3 and Z=4. The final residual index is converged to R =1.5%, wR2=3.5%. BaTe2 is a Zintl type compound isostructural to SrS2. Pairs of tellurium atoms form dimeric units (Te2)2- with a Te-Te sepa ration of 2.7722(8) angstrom. The synthesis of BaTe2 at relatively low temperature has provided an alternative and convenient route for prep aring new compounds in this category.