Estimations and implications of the mean binding energy and the fluctuation between the structural units in chalcogenide glasses

The mean binding energy and the fluctuation between the structural units in chalcogenide glassy systems are estimated by using the Bond Strength-Coordination Number Fluctuation (BSCNF) model. Chalcogenide glasses can be considered to be formed by an agglomeration of structural units. For this kind of glasses, the structural units are connected to each other by weak intermolecular forces. From the results obtained in the present study, it is suggested that the binding energy estimated by the BSCNF model corresponds to the intermolecular forces between the structural units. The analysis by the BSCNF model also suggests that the viscous flow or the structural relaxation results by breaking the weaker parts of the bonds in the intermolecular connections. This picture of the viscous flow is in agreement with the structural model of covalent glasses and the photo-induced properties in chalcogenide glasses proposed by other authors.