Raman Scattering Study of the Alpha-Beta Phase Transition in Quartz
1967; American Physical Society; Volume: 19; Issue: 7 Linguagem: Inglês
10.1103/physrevlett.19.361
ISSN1092-0145
AutoresS. M. Shapiro, Donald C. O’Shea, H. Z. Cummins,
Tópico(s)Spectroscopy and Quantum Chemical Studies
ResumoThe Raman spectrum of crystalline quartz has been studied at temperatures between -196 and 615\ifmmode^\circ\else\textdegree\fi{}C. A weak mode of symmetry ${A}_{1}$ with room-temperature Raman shift of 147 ${\mathrm{cm}}^{\ensuremath{-}1}$ is found to grow in intensity and move towards zero Raman shift as the alpha-beta transition is approached. This mode, rather than the 207-${\mathrm{cm}}^{\ensuremath{-}1}$ mode, appears to play the fundamental role in the phase transition. The temperature dependence of the Raman shift of the new mode is given by ${\ensuremath{\nu}}^{2}\ensuremath{\sim}{|T\ensuremath{-}{T}_{c}|}^{\ensuremath{\gamma}}$ with $0.4<~\ensuremath{\gamma}<~0.5$.
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