Structural and physical–chemical properties of the CuGa5Se8, CuGa3Se5 and CuIn3Se5 compounds Original Research Article

Large-block (8×4×3 mm3) CuGa5Se8 crystals were obtained by the horizontal Bridgman method. Homogeneous CuGa3Se5 and CuIn3Se5 single crystals 12 mm in diameter and up to 40 mm in length were grown by directed crystallization of the melt. All three compounds were found to have the chalcopyrite-related structure. The melting points of these compounds were defined by means of the differential thermal analysis. The lattice parameters a and c as well as the axial thermal expansion coefficients αa and αc were determined as a function of temperature in the range from 90 to 650 K by the X-ray diffraction method. It is revealed that for all three compounds the coefficients of expansion along the a-axis are larger than those along the c-axis over the entire temperature range studied.