Abstract
The present work deals with the effect of S additions on glass density, molar volume, compactness and optical properties of Different compositions of As0.20Se0.80-xSx (0.0 <= x <= 0.55 at. %) glasses. The coordination number Se and S atoms is the same N-Se = N-S = 2. Therefore, the coordination number of the present glasses is constant and equal to 2.2. The glass density, compactness, the Tauc parameter root beta and the Urbach energy are decrease with the addition of S amount whereas the molar volume and the optical gap are increases. Two stoichiometric glasses were observed. The first at 25 at.% S content with Se-S and As-Se bonds and the second at 55 at.% S content with As-S and Se-S bonds. The obtained results are consistent with each others and well discussed in terms of the chemical bonds and the Mott and Davis model.