Effect of arsenic atom substitute with antimony on crystallization processes and thermal stability of the (Sb, As)-S-I system

Abstract

Non-isothermal differential scanning calorimetry measurements of SbxAs37-xS48I15 chalcogenide glasses for x=0, 7, 12, 22, 32 and 37at.% at different heating rates were applied for the analysis of the crystallization processes and thermal stability. The activation energies of glass transition (Eg) and crystallization (Ec) were obtained. Methods based on the temperature of peak and methods based on the shape of peak of crystallization were used for Ec calculations. The activation energies of glass crystallization were determined for the Sb37S48I15 glass, as well as the value of the Avrami index n using the Matusita–Sakka theory. The analysis showed that the detected crystallization processes are characterized by the value n which indicates that volume nucleation and three-dimensional growth are involved. Depending on the model used, the values of this parameter for SbSI ranged from 122(14) to 133(14) kJ/mol, whereas for the structural unit Sb2S3, the values were in the range from 160(18) to 176(50) kJ/mol. Values of Ec for Sb2S3 structural unit, correspond to values which can be found in the literature. Eg values are in the range from 222(40) kJ/mol to 302(8) kJ/mol, depending on Sb content. Reducing of thermal stability against crystallization can be explained by the exchange of the elements from the same group of the Periodic Table (As and Sb) and similar nature of the analogous structural units, involving no change in the coordination number, whereas the share of the ionic bond in them is changed.