PHASE EQUILIBRIA IN THE Cu2Se–SnSE–Sb2Se3 SYSTEM

E.N Ismayilova,I.B Bakhtiyarly,L.F Mashadiyeva,M.B Babanly

doi:10.32737/0005-2531-2022-1-73-82

Abstract

Phase equilibria in the Cu2Se–SnSe–Sb2Se3 quasi-ternary system has been studied by differential thermal analysis and powder X-ray diffraction. Some polythermal sections, isothermal sections at 300 K of the phase diagram and the projection of the liquidus surface are constructed. The regions of primary crystallization of phases, the nature and temperatures of non- and monovariant equilibria have been determined. The phase diagram of the SnSe–CuSbSe2 quasi-binary section has been refined. It was found that a quaternary compound CuSnSbSe3 is formed in the system by the peritectic reaction. This compound exists in a narrow range ~(650–723 K) temperatures. In addition, in the studied Cu2Se–SnSe–Sb2Se3 system, limited regions of solid solutions based on the SnSe, Sb2Se3, CuSbSe2 and SnSb2Se4 compounds have also been revealed

Highlights

This paper presents new experimental data on phase equilibria in a quasi-ternary Cu2Se– SnSe–Sb2Se3 system
We found that in the SnSe–Sb2Se3 system, a ternary compound Sn2Sb2Se5 and an intermediate -phase with a homogeneity range of 48–60 mol.% Sb2Se3 are formed
Based on the DTA data, we plotted a new version of the T-x diagram of this section (Figure 1)

Summary

Introduction

Complex copper chalcogenides attract attention due to their photoelectric, thermoelectric, nonlinear optical and other properties [1– 6]. The CuSbSe2 compound melts congruently at 753 К [31] This compound has the diamond-like structure with Cu atoms occupied in the center of Se-formed tetrahedrons and crystallizes in the orthorhombic system, with space group Pnma and lattice parameters at room temperature: a = 6.467 Å, b = 4.045 Å and c = 15.048 Å; Z = 4 [32]. We found that in the SnSe–Sb2Se3 system, a ternary compound Sn2Sb2Se5 and an intermediate -phase with a homogeneity range of 48–60 mol.% Sb2Se3 are formed. This region includes the stoichiometric compositions of ternary compounds SnSb2Se4 and Sn2Sb6Se11, previously indicated in [35–38]. The radiographs were indexed using the Topas V3.0 Software program (Bruker)

Results and discussion

Conclusion

Applications of Chalcogenides