In situ Raman scattering measurements have been obtained for vitreous ZnCl2 compressed isothermally to 25 GPa. The Raman spectra indicate that, in contrast to other tetrahedral framework glasses, when compressed at room temperature glassy ZnCl2 crystallizes to the high-pressure CdCl2-structured phase between 2.3 and 3.0 GPa; on decompression, the high-pressure phase remains until 1.1 GPa, where it then reverts to γ-ZnCl2. On recompression the γ-ZnCl2 phase converts to the CdCl2 phase at 2.5 GPa and backtransforms at 1.1 GPa upon decompression. We suggest that a density-driven phase separation in the supercooled liquid regime underlies the amorphous-to-crystalline transition of ZnCl2 and other glassy materials.
|Original language||English (US)|
|Number of pages||5|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Mar 1 2000|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics