POWDER X-RAY DIFFRACTION STUDY OF THE Cu3SbS3-CuI SYSTEM

The nature of phase equilibria in the Cu3SbS3-CuI binary system over the entire concentration range were studied by means of the powder X-ray diffraction analysis (PXRD) for the first time at room temperature. It was found that the sample containing 66.7 mol.% CuI composed of a single phase and has a powder diffraction pattern completely different from the constituent phases of the system under study. The crystal lattice type and parameters, that were determined on the basis of the X-ray diffraction pattern of this sample using the TOPAS 4.2 and EVA computer programs are fully consistent with the literature data of the Cu5SbS3I2 four-component compound. The copper (I) iodide rich samples of the system consist of a two-phase mixture of Cu5SbS3I2 and CuI phases. However, the system is unstable in the Cu5SbS3I2-Cu3SbS3 composition range. In this concentration interval, the system is characterized by complex physico-chemical interaction of the initial components.