HIGH-PRESSURE DENSIFICATION OF SILICA GLASS - A MOLECULAR-DYNAMICS SIMULATION

Citation
Rg. Dellavalle et E. Venuti, HIGH-PRESSURE DENSIFICATION OF SILICA GLASS - A MOLECULAR-DYNAMICS SIMULATION, Physical review. B, Condensed matter, 54(6), 1996, pp. 3809-3816
Citations number
59
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Condensed Matter
ISSN journal
0163-1829
Volume
54
Issue
6
Year of publication
1996
Pages
3809 - 3816
Database
ISI
SICI code
0163-1829(1996)54:6<3809:HDOSG->2.0.ZU;2-0
Abstract
We have performed a molecular-dynamics simulation for a sample of amor phous SiO2 subject to a compression-decompression process at ambient t emperature, using a recently proposed two-body potential model. For mo derate compression the simulated glass maintains the ideal tetrahedral coordination and displays reversible elastic behavior. For compressio ns beyond 6 GPa, the glass becomes anelastic and its density and avera ge atomic coordination increase irreversibly. Density, compressibility , and structure of the simulated material compare favorably with the e xperiments on both undensified and densified SiO2 glass. The stability of Si-O coordination greater than four in samples subject to high pre ssure appears to drive the densification process.