A structural analysis of the vitreous silica surface via a molecular dynamics computer simulation

S. M. Levine, Steve Garofalini

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

Molecular dynamics computer simulations were used to study surfaces of pure silica glass. The potentials used here were those previously established to model bulk silica and have been extended to study surface relaxation in a perfect vacuum. A large number of surfaces were made using different starting configurations; system sizes, and cooling procedures. Following "fracture," many broken bonds rearranged in response to the changes in the net forces in the surface region. After this reconstruction, the simulations showed the expected general features observed experimentally, such as a prevalence of oxygen atoms at the outermost surface, nonbridging oxygens, and strained siloxane bonds. Threefold silicons (similar to e′ centers) were initially present in the "fractured" surfaces but most often were incorporated into the network tetrahedrally after reconstruction. Other defects produced during the reconstruction were five coordinated silicons and more importantly, edge sharing tetrahedra, forming the strained siloxane bonds. Bond angles and bond lengths for each defect were determined, showing good agreement with previously published results as well as providing new information. Finally, estimations for silanol concentrations were made which compare well with experimentally determined coverages. The computer simulation technique used here adequately reproduces many of the structural and dynamic characteristics of silica glass surfaces.

Original languageEnglish
Pages (from-to)2997-3002
Number of pages6
JournalJournal of Chemical Physics
Volume86
Issue number5
Publication statusPublished - 1987

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Fused silica
structural analysis
Structural analysis
Molecular dynamics
computerized simulation
molecular dynamics
silicon dioxide
Computer simulation
Siloxanes
Silicon
siloxanes
silica glass
Surface relaxation
Oxygen
Defects
Bond length
Silicon Dioxide
defects
silicon
tetrahedrons

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

A structural analysis of the vitreous silica surface via a molecular dynamics computer simulation. / Levine, S. M.; Garofalini, Steve.

In: Journal of Chemical Physics, Vol. 86, No. 5, 1987, p. 2997-3002.

Research output: Contribution to journalArticle

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