Synthesis and Structural Characterization of Ba2CdTe3

The new ternary compound Ba2CdTe3 has been prepared by the reaction of a stoichiometric mixture of elements at 700°C. Its structure was determined via the Rietveld refinement method using powder X-ray diffraction with Rp/Rwp(%)=6.54/8.67. Ba2CdTe3 crystallizes in space group Pnma (No. 62) of the orthorhombic system with Z=4 and a=9.8198(2) ?, b=4.7436(1) ?, c=19.0638(5) ?. It is isotypic to Ba2MnS3 and K2AgI3. The structure consists of one-dimensional chains of 1infinity [CdTe2/2Te2]4- separated by Ba2+ cations. The chain is made of corner-sharing CdTe4 tetrahedra. Each Ba atom is coordinated to seven tellurium atoms to form a trigonal prism with one rectangular face capped by a Te atom.