The selenium based chalcogenide glasses with low content of As and Sb: DSC, StepScan DSC and Raman spectroscopy study

Abstract

Thermal properties and structure of As x Se 100− x and Sb x Se 100− x glass-forming systems ( x = 0, 1, 2, 4, 8 and 16) were studied by conventional and StepScan DSCs and Raman spectroscopy. Compositional dependence of the glass transition temperature, T g, was determined from reversible part of StepScan DSC records and discussed. The attention was also focused on the crystallization of undercooled melts of these systems. It was found that only selenium crystallizes from undercooled melts of As–Se system and its tendency to crystallize decreases markedly with increasing As content, for arsenic content higher than 4 at.% no crystallization was observed. In the case of Sb–Se system Sb 2Se 3 crystallizes in the first step followed by trigonal selenium crystallization from non-stoichiometric undercooled melt. Sb 2Se 3 crystallizes from incongruent melt with crystallization enthalpy Δ H c(Sb 2Se 3) = −52 ± 2 J/(g of Sb 2Se 3), Johnson–Mehl–Avrami kinetics of crystallization and kinetic exponent close to 3 was found. Raman spectra were measured to obtain basic information on the structure of both glassy systems.