Boroxol rings in liquid and vitreous B2O3 from first principles | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Boroxol rings in liquid and vitreous B2O3 from first principles

Type de publication:

Journal Article

Source:

Physical Review Letters, Volume 101, Ticket 6 (2008)

ISBN:

0031-9007

Numéro d'accès:

WOS:000258538600036

Mots-clés:

Minéralogie, UMR 7154

Résumé:

We investigate the structural and vibrational properties of glassy B2O3 using first-principles molecular dynamics simulations. In particular, we determine the boroxol rings fraction f for which there is still no consensus in the literature. Two numerical models containing either a low or a high level of boroxol rings are tested against a gamut of experimental probes ( static structure factor, Raman, B-11 and O-17 NMR data). We show that only the boroxol-rich model ( f = 75%) can reproduce the full set of observables. Total-energy calculations show that at the glass density, boroxol-rich structures are favored by about 6 kcal/(mol boroxol). Finally, the liquid state is explored in the 2000-4000 K range and a reduction of f to 10%-20% is obtained.