The effect of adding CsCl content on physicochemical properties of (GeS2–Sb2S3)100-x(CsCl)x (0 ≤ x ≤ 40 mol%) chalcohalide glasses

The physico-chemical properties of (GeS 2 –Sb 2 S 3 ) 100-x (CsCl) x (0 ≤ x ≤ 40 mol%) chalcohalide glasses were theoretically studied. The band gap (E g ) of the studied glass system was estimated and was found to increase by adding the CsCl content. Furthermore, the positions of the valence band and conduction band edges was determined. The results reveal that the molar volume (V m ) of the studied samples increased while the density ( ρ ) and the number of atoms per unit volume (N) decreased with increasing the CsCl content. The overall coordination number (CN), constraints number (N s ) and overall mean bond energy () were computed using the chemical bond approach and were found to decrease. In contrast, the number of lone-pair electrons (LP) and cohesive energy (CE) increased. Finally, the glass-transition temperature (T g ) was also estimated based on the overall mean bond energy, and was found to decrease with increasing the CsCl content.