Structural refinement of the ternary chalcogenide compound Cu2GeTe3 by X-ray powder diffraction

The Cu2GeTe3 compound crystallizes in the Imm2 (N° 44) space group, Z = 2, with a = 12.641(1) A, b = 4.2115(2) A, c = 5.9261(2) A, V = 315.49(3) A3. Its structure was refined from X-ray powder diffraction data using the Rietveld method. The refinement of 23 instrumental and structural variables led to Rp = 8.2%, Rwp = 11.6%, Rexp = 6.8%, RB = 11.2 % and S = 1.7, for 5501 step intensities and 253 independent reflections. This compound is isostructural with Cu2GeSe3, and consists of a three-dimensional arrangement of slightly distorted CuTe4 and GeTe4 tetrahedra connected by common corners. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)