Abstract

Chemical interaction in the Sb₂Te₃ - Tb₂Te₃ system was studied using physicochemical analysis methods (differential thermal analysis, X-ray phase analysis, microstructural analysis, microhardness measurement and density determination). Based on the analysis results, a phase diagram of the Sb₂Te₃ - Tb₂Te₃ system was constructed. It was found that the Sb₂Te₃ - Tb₂Te₃ section is a quasi-binary section of the Tb-Sb-Te ternary system and belongs to the eutectic type. It is evident from the phase diagrams that in the Sb₂Te₃ - Tb₂Te₃ section, a new ternary incongruently melting compound of the TbSbTe3 composition is formed by a peritectic reaction at a temperature of 980K with a component ratio of 1:1. According to the results of X-ray phase analysis, it was established that the TbSbTe3 compound crystallizes in orthorhombic syngony with the lattice parameters: a =2.35, b=12.76, c=4.86 Å. The solubility of Tb₂Te₃ in Sb2Te₃ is 3.0 mol.% at 300K, respectively. The electrophysical properties of the TbSbTe₃ compound have been studied. It has been shown that this compound is an «n»-type semiconductor, with a band gap of ~0.21eV.

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