Abstract
First-principles molecular dynamics simulations are used to study the structural properties of liquid and crystalline . We reproduce the experimental structure factor with confidence and fully describe the pair-correlation functions and the local structure of the liquid. It is shown that, unlike other group IV chalcogenides such as , does not display tetrahedral ordering in the liquid and contains a large amount of fivefold tin atoms with selenium atoms lying in an equatorial plane and at the edges of the polyhedra. A certain number of homopolar defects are found whose rate is substantially lower however than in . Compared to the crystalline system the density in the liquid decreases by 8.5%, which is accompanied by a decrease in the atomic coordination. Local distortions as found in typical phase-change materials are present in .
4 More- Received 18 July 2008
DOI:https://doi.org/10.1103/PhysRevB.78.224209
©2008 American Physical Society