Abstract
The radial distribution function (RDF) of As30Se70-xSnx amorphous films was obtained by X-ray diffraction. Depending on the composition and preparing conditions, the short-range order of the melt-quenched, and thermally evaporated As30Se70-xSnx (x = 0, 3 at.%) is described. Structural parameters such as interatomic distances and bond angles were derived and proposed as a good statistical description of the glasses under study. Both the disorder network structure of the glass matrix and the transport properties have been studied according to the chemical properties of Sn as a doping element. The activation energies calculated from dc conductivity is obtained. The effect of composition and average coordination number N-c, on the number of topological constraints N-con, the number of lone-pair electrons L, the mean atomic volume V-a and the glass transition temperature T-g have been studied, in the light of recent model proposed for covalent random network. The occurrence of this dependence leads to the conclusion that Sn has a marked effect on the electronic state of the host glass. (c) 2007 Elsevier B.V. All rights reserved.