On the glass transition temperature Tg against molar volume Vm plotting in arsenoselenide glasses

Abstract

Dependence of glass transition temperature Tg (K) on overall mean bonding energy E (kJ/mol) in arsenoselenide glass reexamined under per-atom calculations is shown to obey linearized master equation Tg ≅ 418⋅(E–1.13). Compositional variations in Tg against molar volume Vm are plotted for g-AsxSe100-x taken within (0 ≤ x ≤ 65) domain assuming preferential cohesive Van der Waals (VDW) bonding between network-constituting entities. The Tg values are found to vary as inverse-αth power of Vm, attaining distinct values for different networks, in part, 0D-molecular (α = =6/3 = 2), 1D-chained (α = =5/3), 2D-layered (α = =4/3), and 3D-spatial (α = =3/3 = 1). These variations originated from macroscopic geometry of VDW interaction are linearized in log-log presentation for networks dominated with chain-like 1D-entities (0 ≤ x<~8) and cross-linked 3D-entities (~8 < x< 30–33), while demonstrate non-linear behaviour for cross-linked 3D- and layered 2D-entities (30–33 < x < 40), and layered 2D- and molecular 0D-entities (40 < x < 65). Appearance of molecular entities in g-AsxSe100-x (40 < x < 65) results in self-terminated loop in log–log plotting of Tg(1/Vm) dependence.