Charge Transport and Thermo-emf in TlFe1−xGaxS2 Solid Solutions

Solmaz Mustafaeva,Salim Asadov

doi:10.1155/2019/9285359

Abstract

TlFe1−xGaxS2 solid solutions have been prepared by direct elemental synthesis. The dependences of the thermoelectric properties and DC conductivity on temperature have been studied in TlFe1−xGaxS2 solid solutions. In terms of hopping mechanism of charge transfer, the parameters of localized states in the forbidden gap of TlFe1−xGaxS2 have been evaluated. The type of conductivity has been determined from the temperature dependences of thermoelectric power of TlFe1−xGaxS2 solid solutions.

Highlights

In [4], the T − x phase diagram of the TlFeS2−TlGaS2 system has been constructed
At an annealing temperature of 933 K, the solid solutions based on the end-members extend to 5 mol.% TlFeS2 and 10 mol.% TlGaS2. e band gap of TlGa1−xFexS2 (x 0; 0.005; 0.01) single crystals has been shown to decrease with increasing Fe concentration and increase with increasing temperature
From the nature of the temperature dependence of the magnetic susceptibility and its magnitude, it follows that the TlFeS2 is in the paramagnetic state at room temperature, while TlGaS2 shows a typical diamagnetic state [5]. e temperature dependence of the magnetic susceptibility curve of TlFeS2 revealed anomalies, indicating phase transitions in this compound

Summary

Introduction

In [4], the T − x phase diagram of the TlFeS2−TlGaS2 system has been constructed (simple eutectic system, eutectic at 80 mol.% TlGaS2 with a melting point of 953 K). Erefore, the study of the effect of doping components on the physical parameters, the mechanism of charge transfer, and temperature-concentration dependences of thermoelectric power, as well as the determination of correlations between them in materials of the TlFeS2 type is an urgent task. Of the temperature dependence of conductivity and thermoelectric power of materials based on TlFeS2, the composition of which is partially chemically modified, has not been systematically studied.

Results

Conclusion