Refining glass structure in two dimensions

Mahdi Sadjadi, Bishal Bhattarai, D. A. Drabold, Michael Thorpe, Mark Wilson

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Recently determined atomistic scale structures of near-two dimensional bilayers of vitreous silica (using scanning probe and electron microscopy) allow us to refine the experimentally determined coordinates to incorporate the known local chemistry more precisely. Further refinement is achieved by using classical potentials of varying complexity: one using harmonic potentials and the second employing an electrostatic description incorporating polarization effects. These are benchmarked against density functional calculations. Our main findings are that (a) there is a symmetry plane between the two disordered layers, a nice example of an emergent phenomena, (b) the layers are slightly tilted so that the Si-O-Si angle between the two layers is not 180° as originally thought but rather 175±2°, and (c) while interior areas that are not completely imagined can be reliably reconstructed, surface areas are more problematic. It is shown that small crystallites that appear are just as expected statistically in a continuous random network. This provides a good example of the value that can be added to disordered structures imaged at the atomic level by implementing computer refinement.

Original languageEnglish (US)
Article number201405
JournalPhysical Review B
Volume96
Issue number20
DOIs
StatePublished - Nov 10 2017

Fingerprint

Scanning probe microscopy
refining
Fused silica
Crystallites
Refining
Density functional theory
Electrostatics
Polarization
Glass
Scanning electron microscopy
glass
crystallites
electron microscopy
chemistry
electrostatics
silicon dioxide
microscopy
harmonics
scanning
probes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Sadjadi, M., Bhattarai, B., Drabold, D. A., Thorpe, M., & Wilson, M. (2017). Refining glass structure in two dimensions. Physical Review B, 96(20), [201405]. https://doi.org/10.1103/PhysRevB.96.201405

Refining glass structure in two dimensions. / Sadjadi, Mahdi; Bhattarai, Bishal; Drabold, D. A.; Thorpe, Michael; Wilson, Mark.

In: Physical Review B, Vol. 96, No. 20, 201405, 10.11.2017.

Research output: Contribution to journalArticle

Sadjadi, M, Bhattarai, B, Drabold, DA, Thorpe, M & Wilson, M 2017, 'Refining glass structure in two dimensions', Physical Review B, vol. 96, no. 20, 201405. https://doi.org/10.1103/PhysRevB.96.201405
Sadjadi M, Bhattarai B, Drabold DA, Thorpe M, Wilson M. Refining glass structure in two dimensions. Physical Review B. 2017 Nov 10;96(20). 201405. https://doi.org/10.1103/PhysRevB.96.201405
Sadjadi, Mahdi ; Bhattarai, Bishal ; Drabold, D. A. ; Thorpe, Michael ; Wilson, Mark. / Refining glass structure in two dimensions. In: Physical Review B. 2017 ; Vol. 96, No. 20.
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