Compositional dependence of the physical properties in a-Ge–Se–In glassy semiconductor

Physical properties viz. mean bond energy (〈E〉), glass transition temperature (Tg), cohesive energy (CE), average heat of atomization (Hs¯), density (ρ), molar volume (Vm) and compactness (δ) of Ge20Se80−xInx (x=0, 5, 10, 15, 20) bulk glassy alloys have been examined theoretically. Mean bond energy (〈E〉) is proportional to glass transition temperature (Tg). The cohesive energy (CE) of the investigated samples has been calculated using the chemical bond approach (CBA) method. The relation between photon energy (E04) is discussed in terms of average heat of atomization Hs¯ and average coordination number (〈r〉). The compactness (δ) of the structure of the glass is determined from measured density of the glasses in order to display the chemical threshold in the system using Phillips–Thorpe topological models. Maximum of the compactness has been observed at floppy to rigid transition point occurring in networks. Molar volume (Vm) has been calculated from the experimentally measured densities and on the basis of number of atoms per unit volume (N); Vm follows the same trend as that of optical band gap.