Does the $8-N$ bonding rule break down in As${}_2$Se${}_3$ glass?

Abstract

The local coordination numbers of As${}_2$Se${}_3$ glass were determined by a combination of anomalous x-ray scattering experiments, reverse Monte Carlo calculations, and {\it ab initio} molecular dynamics simulations. The well-known `8-$N$ bonding rule' proposed by Mott breaks down around the As atoms, exceeding the rule by 7--26%. An experimental prediction based on mean-field theory agrees with the present experimental and theoretical results. The fourfold coordinated As atoms likely form As-As wrong bond chains rather than ethan-like configurations, which is identified as the origin for the breakdown of the `8-$N$ bonding rule'.

6 pages, 6figures, 1table, submitted to Europhysics Letters

Cited by in corpus (1)

• Crucial effect of glass processing and melt homogenization on the fragility of non-stoichiometric chalcogenides