Structural and short-range order analysis of glassy system

To understand the effects of structural features and to locate their signatures in the As-Ag-Te glassy system, various properties were studied as a function of average coordination number, < r >. The structure of the sample is analyzed by X-ray diffraction technique and is found to be crystalline. The d-spacing and the lattice parameters of the samples were calculated. The structural parameters were discussed on the basis of Ag (silver) effect on As-Ag-Te glassy system. Structural investigations on these compositions revealed the polycrystalline nature of compositions with the presence of hexagonal As-Ag-Te phases. Grain size increased with the Ag content and parameters of unit cell are determined. The variations in the mean atomic volume, V. and the glass transition temperature, T-g, for glass transition, with composition have been reported. The change in thermal parameters was measured using differential thermal analysis (DTA). The results of the program are in agreement with those of analytical method and realized by binding energy represented by the cohesive energy values. The generalized '8-n' rule was used to estimate the average coordination number. Obtained results were treated in the frame of chemical bond approach. We estimated some of physical parameters viz, mean bond energy, glass transition temperature, cohesive energy, average single bond energy, density, compactness and molar volume of all bulk samples. Our experimental and theoretical results were discussed in light of the topological bonding structure, which involves a hierarchy of correlation ranges in short-range order. (C) 2010 Elsevier B.V. All rights reserved.