Eur. Phys. J. B 84, 11-16 (2011)
https://doi.org/10.1140/epjb/e2011-20405-6

Regular Article

Phase stability and elasticity of Sc₂O₃ at high pressure

Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education & School of Earth and Space Sciences, Peking University, Beijing 100871, P.R. China

^a e-mail: xiang.wu@pku.edu.cn

Received: 30 May 2011
Received in final form: 9 September 2011
Published online: 26 October 2011

Abstract

An investigation into the high-pressure behavior of Sc₂O₃ was conducted using first-principle calculations based on density functional theory within the generalized gradient approximation. Nine candidate phases were considered and simulated, C-, B-, A-RES, Rh₂O₃(II), Gd₂S₃, U₂S₃, Al₂Er₃, corundum and PPv respectively. Our results demonstrate phase transitions of Sc₂O₃ from C- to B-RES phase at 15 GPa, then to Gd₂S₃ phase at 18 GPa. Elastic constants of Sc₂O₃ present softening from about 270 GPa to 337 GPa, associated with a semiconductor-to-metal crossover. The Gd₂S₃-type Sc₂O₃ is both mechanically and dynamical stable at least up to 302 GPa supported by the mechanically stable criteria and the phonon spectrum.