A Comprehensive Study of Sn-Ga2Te3-SnTe Amorphous Alloys: Glass Formation and Crystallization Kinetics

Abstract

In this paper, newly developed tellurium-based [(Ga2Te3)34(SnTe)66]100-x-Snx amorphous alloys were prepared by the melt-spun method, with a linear velocity of 40 m/s and injection pressure of 20 kPa under an Ar atmosphere. The glass-forming region was identified in the range of x = 0 to 10 mol%. The glass transition temperature Tg and crystallization onset temperature Tc decreased monotonically with the increasing Sn content in the whole compositional range, resulting in the decrease in the stability criterion ΔT from 33 K (S2) to 23 K (S10). The crystallization kinetics were systematically investigated based on the differential scanning calorimeter (DSC) under non-isothermal conditions. The activation energies of the S8 amorphous sample determined by Kissinger and Ozawa equations were Eg (201.1~209.6 kJ/mol), Ec (188.7~198.3 kJ/mol), Ep1 (229.8~240.1 kJ/mol) and Ep2 (264.2~272.6 kJ/mol), respectively. The microscopic structure of the S8 amorphous sample and its annealed glass-ceramics were also analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). The crystalline products were identified as having a SnTe phase (primary crystalline phase) and Ga6SnTe10 phase, thus providing a promising candidate for the development of high-performance thermoelectric glass-ceramic materials.