(CuAlSe2)1-X(TaSe)XALLOY SYSTEM (0 ≤ X≤ 0.5): X-RAY DIFFRACTION, DIFFERENTIAL THERMALANALYSIS AND SCANNING ELECTRON MICROSCOPY MEASUREMENTS

Abstract

Polycrystalline samples belonging to the (CuAlSe2) 1-x (TaSe) xalloys system, in the composition interval 0 ≤ x ≤ 0.5, were synthesized by the melt and anneal method. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (DTA) techniques were used for the characterization of the products. From XRD it can be observed a chalcopyrite-like single phase in the composition range 0≤ x ≤0.1, with lattice parameters very close to CuAlSe2and two-phases, chalcopyrite-like and hexagonal-Cu0.52TaSe2, for 0.1 < x ≤ 0.5. By SEM, the stoichiometry for all samples had been measured and the new phase was identified as (Cu0.4Al0.3)TaSe2. From DTA the respective phase transitions with temperature were obtained. Using the experimental information, a preliminary T-x phase diagram was proposed.