Correlation between Raman spectroscopy and mechanical properties of As-Sb-S-I chalcogenide glasses

Present investigation explores the structural changes that occur in glass network as a function of compositional variation through Raman spectra of As-Sb-S-I chalcogenide glasses and correlated with their bulk mechanical properties. In this study, a series of six glasses are prepared by melt quenching technique. The glass without iodine (G1) is assigned as base glass. The rest of the glass compositions are designed with iodine content either at 10 or 20 mol% and simultaneously varying the As/Sb mol% ratio. The effects of iodine variation in the glass matrix are clearly evident from their Raman spectra as well as bulk mechanical properties which are further validated by theoretical estimated average coordination number <r>. Raman spectra analysis indicates that the peak around 150 cm(-1) corresponding to Sb-S bonds increases in amplitude and appearance of peak around 233 cm(-1) of As-S bonds in antimony and arsenic rich glasses, respectively. In addition, an intense peak around 490-495 cm(-1) and weak peak around 233 cm(-1) which are attributed to stretching vibrations S-S and As-S bonds respectively in As2S3 units can be seen only in arsenic rich glasses. The elastic modulus values denote the dependence on antimony content while Vickers hardness values are decreasing with an increase in iodine content. The Raman spectra of raw materials used in glass preparation are also analysed to compare the bonds present in crystalline raw materials to that of amorphous structure in the prepared glasses.