Rietveld refinement for CuInSe2 and CuIn3Se 5

Rietveld refinements for copper indium selenides CuInSe2 and CuIn3Se5 and their mixture were performed using data collected at a Bragg-Brentano diffractometer. The values of lattice parameters, axial ratio and positional parameters are discussed and compared to available literature data for single crystals and polycrystals. Results for CuInSe 2 give a0=5.78149(1) Å and c0=11.61879(4) Å. The positional parameter x is determined to be equal 0.2271(4). Refinements for CuIn3Se5 give an indication concerning the choice of a structural model for this compound. Namely, the best fit is obtained for a model based on I4¯2m space group, yielding a composition close to the experimental one and the lattice parameters a 0=5.75812(2) Å and c0=11.53593(7) Å. Parameters of this model are discussed. © 2003 Elsevier B.V. All rights reserved.