CRYSTAL-STRUCTURE OF SYNTHESIZED CUGA0.5IN0.5TE2 DETERMINED BY X-RAY-POWDER DIFFRACTION USING THE RIETVELD METHOD

A full profile X-ray powder diffraction structure refinement has been carried out on a sample of synthesized CuGa0.5In0.5Te2 using graphite monochromatized CuKalpha step-scan data and a profile shape of the Pea rson VII type. The most satisfactory convergence was achieved at R(p) = 0.0483, R(wp) = 0.0641, R(B) = 0.0208 and R(F) = 0.0320, where, R is the Rietveld refinement. The derived structural parameters at 26-degr ees-C are a = 0.610 09(2) nm, c = 1.21 9 79(4) nm an x [Te] = 0.2279(3 ). The ratio between lattice parameters, eta = c/2a = 0.9997 (0) diffe red very slightly from 1, while the non-ideal anion displacements, x [ Te] not-equal 1/4, was manifested by the existence of bond alternation of Cu-Te, Ga-Te and In-Te.