Critical Opalescence in Quartz

Abstract

The intense scattering of light by quartz in the vicinity of the $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\beta}$ transition, first observed by Iakovlev and co-workers in 1955, has been studied by Raman and Brillouin spectroscopy and by visual observation. Our results indicate that the observed "opalescence" does not originate from critical fluctuations of the order parameter but is generated by essentially static domain walls separating microdomains of opposite electrical twins.