Crystal structure refinement of CuxAg1-xInTe2 bulk material determined from X-ray powder diffraction data using the Rietveld method

摘要

The influence of the Cu-content in the quaternary compounds CuxAg1-xInTe2 (0 less than or equal to x less than or equal to 1) on the structural properties of the bulk material was discussed. Bulk ingot materials of CuxAg1-xInTe2 solid solutions (x = 0.0, 0.25, 0.50, 0.75 and 1.0) have been synthesized by fusion of the constituent elements in the stoichiometric ratios in vacuum-sealed silica tubes. The materials compositions were confirmed by using energy dispersive analysis of X-rays (EDAX). X-ray powder diffraction measurements were performed for all the prepared samples at 300 K in step scanning mode. The analysis of X-ray data has indicated that the crystal structure of the prepared materials with different compositions is single-phase polycrystalline materials corresponding to the tetragonal chalcopyrite structure with space group 142d. The crystal structural parameters were refined by Rietveld method using the Full Prof program. The refined lattice constants (a and c), anion positional parameter, u, and the determined bond distances and angles were found to vary with composition, x, attaining zero tetragonal distortion at x approximate to 0.75, which corresponds to an ideal tetragonal unit cell. [References: 18]