Abstract

Chemical interactions in the Sb₂Se₃-TbSe system were studied using physicochemical analysis methods (differential thermal analysis, X-ray diffraction, microstructural analysis, microhardness measurements, and density determination). Based on the analysis results, a phase diagram of the Sb₂Se₃-TbSe system was constructed. It was established that the Sb₂Se₃-TbSe cross section is a quasi-binary cross section of the Tb-Bi-Se ternary system and is eutectic. In the Sb2Se -based system, a solid solution region containing 8mol.% TbSe forms at room temperature. The solid solution area, determined by microstructural analysis, is 17mol.% at a eutectic temperature of 823K and 5mol.% TbSe at room temperature. The phase diagrams show that a new ternary compound with incongruent melting properties, TbSb₄Se₇, is formed in the Sb₂Se₃-TbSe section as a result of a peritectic reaction at 863K with a component ratio of 1:2. X-ray diffraction analysis revealed that TbSb₄Se₇ crystallizes in an orthorhombic system with lattice parameters a=16.762; b=23.860; c=4.137Å. The solubility of TbSe in Sb₂Se₃ 3.0mol% at 300K. Eutectic point coordinates: 10-15mol.% TbSe, temperature: ~823K.

Keywords:System; Analysis; Crystallization; Phase; Diagram; Temperature