1. Hysteretically reversible phase transition in a molecular glass.
- Author
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Kalkan, B., Sonneville, C., Martinet, C., Champagnon, B., Aitken, B. G., Clark, S. M., and Sen, S.
- Subjects
PHASE transitions ,HYSTERESIS ,GLASS ,DIAMOND anvil cell ,MOLECULAR structure ,EQUATIONS of state ,ARSENIC sulfide ,RAMAN spectroscopy - Abstract
Pressure induced densification in a molecular arsenic sulfide glass is studied at ambient temperature using x-ray scattering, absorption and Raman spectroscopic techniques in situ in a diamond anvil cell. The relatively abrupt changes in the position of the first sharp diffraction peak, FSDP, and the pressure-volume equation of state near ∼2 GPa suggest a phase transition between low- and high-density amorphous phases characterized by different densification mechanisms and rates. Raman spectroscopic results provide clear evidence that the phase transition corresponds to a topological transformation between a low-density molecular structure and a high-density network structure via opening of the constituent As4S3 cage molecules and bond switching. Pressure induced mode softening of the high density phase suggests a low dimensional nature of the network. The phase transformation is hysteretically reversible, and therefore, reminiscent of a first-order phase transition. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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