Structure and imaging properties of As40S60-xSex glasses

Compositional dependence of photo- and thermally induced structural changes in As40S60-xSex layers (x = 0, 20, 30, 40, 60) have been measured. Dispers ion of the refractive index was obtained from the transmission data. Single -oscillator model parameters (oscillator energy, dispersion energy) were es timated. The evolution of the optical dielectric constant was analyzed usin g the Penn model. Raman measurements have shown that two-phase structures c haracteristic of glasses are preserved in As40S60-xSex layers and indicate different bonding structures for as-evaporated, exposed, and annealed layer s. These correspond to photo- and thermally induced changes. The single-osc illator energy changes linearly with composition. The compositional depende ncies of such structurally determined parameters as glass transition temper ature, relaxation enthalpy, specific heat capacity and dispersion energy ar e explained by a small deviation from the statistical effects of substituti on of Se atoms by S in the composition change. (C) 2000 Elsevier Science B. V. All rights reserved.