New Incommensurate Elongated-Triangle Phase in Quartz

P. Saint-Gregoire; I. Luk'yanchuk; E. Snoeck; C. Roucau; V. Janovec

doi:10.1134/1.567212

paper

New Incommensurate Elongated-Triangle Phase in Quartz

arXiv:cond-mat/9511002 · doi:10.1134/1.567212

Abstract

We present for the first time the evidence for a thermodynamically stable incommensurate elongated-triangle ( $E L T$ ) phase in quartz observed by transmission electron microscopy at structural $α - β$ transition. The phase sequence on cooling is: uniform $β$ phase - stripe incommensurate phase (ferroelastic) - incommensurate equilateral-triangle ( $E QT$ ) phase (ferroelectric) - incommensurate $E L T$ (ferroelectric and ferroelastic) - uniform $α$ phase. The $E L T$ blocks could be responsible for the large light scattering in the vicinity of $α - β$ transition.

4 pages revtex file +3 uuencoded compressed postscript figures