Abstract
Selenium is the only easily vitrified elementary substance. Numerous experimental studies of glassy Se (-Se) at high pressures show a large spread in the data on the compressibility and electrical resistivity of -Se. Furthermore, H. Liu et al. [Proc. Natl. Acad. Sci. USA 105, 13229 (2008)] have arrived at the surprising conclusion that the volume of glass increases during pressure-induced crystallization. We have performed high-precision measurements of the specific volume and electrical resistivity of glassy selenium (-Se) at high hydrostatic pressures up to 9 GPa. The measured bulk modulus at normal pressure is GPa and its pressure derivative is . In the pressure range GPa, glassy selenium has an anomalously large negative second derivative of the bulk modulus. The electrical resistivity of -Se decreases almost exponentially with increasing pressure and reaches 20 cm at a pressure of 8.75 GPa. The inelastic behavior and weak relaxation of the volume for -Se begin at pressures above 3.5 GPa; the volume and logarithm of the electrical resistivity relax significantly (logarithmically with the time) at pressures above 8 GPa. Bulk measurements certainly indicate that the volume of -Se glass in the crystallization pressure range is larger than the volumes of both appearing crystalline phases (by 2% and 4%). Therefore, the “volume expansion phenomenon” suggested in [H. Liu et al., Proc. Natl. Acad. Sci. USA 105, 13229 (2008)] is not observed, and the pressure-induced crystallization of glassy selenium is consistent with the laws of thermodynamics.
- Received 31 July 2017
- Revised 3 October 2017
DOI:https://doi.org/10.1103/PhysRevB.96.134111
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