Thermal characterization of glasses from Fe–Sb–S–I system

• DOI: 10.1007/s10973-016-5382-1
• Publication Date: 2016-03-18T20:08:05Z
• Authors: Goran Štrbac; Dragana Štrbac; Svetlana Lukić-Pe...; Mirjana Šiljegović
• Keywords: Endothermic process; Isothermal process; Exothermic reaction; Crystal (programming language)

Thermal characterization of glasses from the Fex[(Sb2S3)0.75(SbSI)0.25)]100−x system, for x = 0, 0.01, 0.1, 0.5, 0.8, 2, 3 and 5 at.%, in the temperature range from 300 to 770 K, was done. The DSC recordings, obtained at different heating rates, revealed three processes: glass transition, crystallization of the corresponding crystalline phases and melting of formed crystalline phases. The glass transition process was characterized with two parameters: onset glass transition temperature T g and apparent activation energy of glass transition E g. Also, the effect of increasing the content of iron in the glass composition on the T g value was determined. The complex crystallization process corresponds to the crystallization of at least two crystalline phases: SbSI and Sb2S3. Due to the considerable overlapping of the exothermic peaks, crystallization kinetics was done for Sb2S3 crystalline phase in the compositions with 0.01 and 0.5 at.% of iron. Analysis was carried out by using the Johnson–Mehl–Avrami theoretical model under non-isothermal conditions. The apparent activation energy of crystal growth E c and the value of the Avrami index n were determined. The value of Avrami index n was determined by using the Matusita–Sakka theory. It has been shown that volumetric nucleation and three-dimensional growth occur. The shape of endothermic peaks on curves, which appear behind the crystallization processes, indicated the simultaneously progress of a multiple processes. It has been found that in addition to the melting of the SbSI phase, the process of thermal decomposition of the glass also begins at given temperatures.