Structure of amorphous GeSe9 by neutron diffraction and first-principles molecular dynamics: impact of trajectory sampling and size effects

Sébastien Le Roux, Assil Bouzid, Kye Yeop Kim, Seungwu Han, Anita Zeidler, Philip S. Salmon, Carlo Massobrio

Research output: Contribution to journalArticle

7 Citations (Scopus)
138 Downloads (Pure)

Abstract

The structure of glassy GeSe9 was investigated by combining neutron diffraction with density-functional theory-based first-principles molecular dynamics. In the simulations, three different models of N = 260 atoms were prepared by sampling three independent temporal trajectories, and the glass structures were found to be substantially different from those obtained for models in which smaller numbers of atoms or more rapid quench rates were employed. In particular, the overall network structure is based on Se_n chains that are cross-linked by Ge(Se4)1/2 tetrahedra, where the latter are predominantly corner as opposed to edge sharing. The occurrence of a substantial proportion of Ge-Se-Se connections does not support a model in which the material is phase separated into Se-rich and GeSe2-rich domains. The appearance of a first-sharp diffraction peak in the Bhatia Thornton concentration-concentration partial structure factor does,however,indicate a non-uniform distribution of the Ge-centered structural motifs on an intermediate length scale.
Original languageEnglish
Article number084502
Number of pages10
JournalJournal of Chemical Physics
Volume145
Issue number8
Early online date23 Aug 2016
DOIs
Publication statusPublished - 28 Aug 2016

Fingerprint Dive into the research topics of 'Structure of amorphous GeSe<sub>9</sub> by neutron diffraction and first-principles molecular dynamics: impact of trajectory sampling and size effects'. Together they form a unique fingerprint.

  • Projects

  • Cite this