Vitreous silica bulk and surface self-diffusion analysis by molecular dynamics

David A. Litton, Steve Garofalini

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Molecular dynamics simulation was used to investigate the kinetics of self-diffusion in the bulk and on the surface of pristine vitreous silica. Multibody potential functions were used to describe interatomic forces. Activation energies were found to be similar for Si and O self-diffusion and did not vary appreciably between self-diffusion in the bulk and on the surface. For both species in the bulk and on the surface, average activation energies ranged from 113-115 kcal/mol. Oxygen self-diffusivity was found to be only slightly higher than silicon self-diffusivity in the bulk and on the surface. Self-diffusion coefficients in the top 3-7 Å of the surface were found to be higher than those of bulk simulations by less than a factor of two. Self-diffusion on the surface was observed to occur by motion of SiO3 and SiO4 polyhedra over several angstroms while bulk self-diffusion involved significant neighbor exchange over similar length scales. Surface diffusion through a vapor phase (via desorption and re-adsorption at a distant location on the surface) was not included in the surface data.

Original languageEnglish
Pages (from-to)250-263
Number of pages14
JournalJournal of Non-Crystalline Solids
Volume217
Issue number2-3
Publication statusPublished - Sep 1997

Fingerprint

Fused silica
surface diffusion
Molecular dynamics
molecular dynamics
silicon dioxide
diffusivity
Activation energy
activation energy
interatomic forces
Surface diffusion
Silicon
polyhedrons
Desorption
diffusion coefficient
simulation
desorption
Vapors
vapor phases
Oxygen
Adsorption

ASJC Scopus subject areas

  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials

Cite this

Vitreous silica bulk and surface self-diffusion analysis by molecular dynamics. / Litton, David A.; Garofalini, Steve.

In: Journal of Non-Crystalline Solids, Vol. 217, No. 2-3, 09.1997, p. 250-263.

Research output: Contribution to journalArticle

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