Raman scattering under pressure and the phase transition in ε-GaSe

• Published in: Physica status solidi. B. Basic research Vol. 235; no. 2; pp. 517 - 520
• Main Authors: Kulibekov, A. M., Olijnyk, H. P., Jephcoat, A. P., Salaeva, Z. Y., Onari, S., Allakhverdiev, K. R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin WILEY-VCH Verlag 01-02-2003; WILEY‐VCH Verlag; Wiley
• Subjects: 63.20.-e; 78.30.-j; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Infrared and raman spectra and scattering; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other nonmetallic inorganics; Physics; Solid-solid transitions; Specific phase transitions; Irreversible processes; Hexagonal lattices; Raman spectra; Inorganic compounds; Pressure effects; Phase transformations; Binary compounds; Experimental study; Gallium selenides; III-VI semiconductors
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200301613

Raman scattering in ε‐GaSe has been investigated at room temperature in a diamond anvil cell by using helium gas as a pressure transmitting medium. The first observation of the solid–solid phase transition under pressure from a hexagonal structure at ambient pressure to a NaCl‐type at around 29.2 GPa is reported. A photoinduced change in the pressurised crystal was observed. The transition under pressure was found to be irreversible at room temperature. It was shown that the pressurised form of ε‐GaSe at ambient conditions most probably belongs to the γ‐type as characterised by an increased intensity of the Raman modes at 234 cm–1 and 250 cm–1.