Study of As2Se3 and As2Se2Te glass structure by neutron- and X-ray diffraction methods

Abstract

Neutron and high-energy X-ray diffraction measurements have been performed on As40Se60 and As40Se50Te10 glasses. Both the traditional Fourier transformation technique and the reverse Monte Carlo (RMC) simulation of the experimental data have been applied to model the 3-dimensional atomic configurations. From the analysis of the partial atomic correlation functions and structure factors the first and second neighbour distances, coordination numbers and bond-angle distributions were calculated. It is established that substitution of Se by Te does not change the basic glassy network structure. For the As-Se bonding is revealed that the first neighbour distance is at 2.42 Å, the average coordination numbers are CNAsSe=2.6±0.1 and CNSeAs=1.8±0.1 atoms and the three-atom-bond angle for <Se-As-Se>, <As-Se-As> configurations is 95°, the same value within limit of error, as obtained from RMC calculations.