Investigation on thermally induced crystallization processes in glassy (As2Se3)100−x(SbSI)x system

Abstract

This paper presents the results of non-isothermal kinetics of crystallization processes in complex amorphous chalcogenide glassy system (As2Se3)100−x(SbSI)x (x = 20, 30, 50, 70 and 80 at.%). The results were obtained using differential scanning calorimetry in non-isothermal regime of work at different heating rates. The crystal growth kinetics was determined by application of several isokinetic and isoconversional theoretical models on experimental data. Kinetic parameters, such as activation energy of crystallization E and the Avrami exponent n have also been determined. It was established that parameter E depends on degree of conversion. The values of Avrami exponent indicated that crystallization mechanism is one-dimensional and nucleation takes place at the surface in the samples with lower SbSI content. For the compositions with higher SbSI amount crystallization process is realized as a volume nucleation. Also, there is an increase in devitrification affinity with the greater presence of structural units of the type Sb2S3 and SbSI, instead of Sb2Se3 and As2Se3. The decrease in thermal stability for the samples with x = 70 and 80 at.% was also noted and confirmed with several parameters using different criteria.