Simulating the amorphization of [alpha]-quartz under pressure

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.9336· OSTI ID:5046856

Binggeli, N ^[1]; Chelikowsky, J R ^[2]; Wentzcovitch, R M ^[3]

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1. Institut Romand de Recherche Numerique en Physique des Materiaux (IRRMA), PHB-Ecublens, 1015 Lausanne (Switzerland)
2. Department of Chemical Engineering and Materials Science and Minnesota Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)
3. The Royal Institution of Great Britain, 21 Albemarle Street, London W1 (United Kingdom)

Extensive molecular-dynamics simulations have been performed within a classical force-field model for the pressure-induced amorphization of quartz. In agreement with earlier molecular-dynamics studies, we find that a phase transition occurs within the experimental pressure range of the amorphization transformation. However, at variance with previous interpretations, we find that the resulting phase is not amorphous. The correlation functions of the equilibrated structure can be shown to be consistent with those of a crystalline phase. Two transformations to ordered structures occur sequentially during the simulations. The first transformation is likely to be related to the recently discovered transition of quartz to an intermediate crystalline phase before its amorphization. The second transformation, instead, yields a compact octahedrally coordinated Si sublattice. The latter structure may be an artifact of the classical force field.

• DOE Contract Number: FG02-89ER45391
• OSTI ID: 5046856
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:14; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
CLASSICAL MECHANICS
CORRELATION FUNCTIONS
FUNCTIONS
MECHANICS
MINERALS
ORDER-DISORDER TRANSFORMATIONS
OXIDE MINERALS
PHASE TRANSFORMATIONS
QUARTZ