Preparation and crystal structure model of a new strontium tantalum sulfide : Sr17Ta10S42

Abstract A new strontium tantalum sulfide, Sr 17 Ta 10 S 42 , has been prepared by sulfurization of a mixture of SrCO 3 and Ta 2 O 5 . The electron and powder X-ray diffraction patterns of the compound were indexed on the basis of a rhombohedral cell with hexagonal setting lattice constants of a = 18.1525(4) and c = 18.6574(4) A. A structure model described in space group R 3 with additional local symmetry operations is proposed based on the Rietveld analysis of the powder X-ray diffraction intensities.