ALEACIONES DE (CuAlSe2)1-X (TaSe)X (0 ≤ X ≤ 0.5): MEDIDAS DE DIFFRACCION DE RAYOS X, CALORIMETRIA DIFERENCIAL DE BARRIDO Y MICROSCOPIA ELECTRONICA DE BARRRIDO

Abstract

Polycrystalline samples belonging to the (CuAlSe2)1-x (TaSe)x alloys 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 CuAlSe2 and 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.