ISSN:
1432-2021
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Abstract A molecular dynamics simulation of quartz at different temperatures both in the a and in the β phase has been conducted. The α-β phase transition could be observed. A phonon analysis of the β-phase confirms and rounds out in a quantitative way the origin of the incommensurate (ic) modulated phase. In particular it traces the optic soft mode at Γ becoming (to a good approximation) a so-called rigid unit mode (RUM) at q≠0, and elucidates its coupling to the transverse acoustic mode which precipitates the incommensurate transition. This success underpins and illuminates the concept of RUMs and their role in structural phase transitions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00200190
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