Phase transition and elastic properties of beryllium sulfide semiconductor under high pressure

¹ School of Science, Chongqing Jiaotong University, Chongqing 400074, P.R. China
² Department of physics, Henan Institute of Education, Zhengzhou 450046, P.R. China
³ Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, P.R. China

^a e-mail: wfbgc@cqjtu.edu.cn

Received: 12 January 2013
Accepted: 20 March 2013
Published online: 30 April 2013

Abstract

In this work, pressure-induced phase transition and elastic properties of BeS II–VI compounds semiconductor are investigated by first-principle method. Phase transition of BeS from direct gap semiconductor phase (ZB) to indirect-gap semiconductor phase (RS) occurs at 51.45 GPa accompanied by 11.23% volume collapse. Phase transition is due to S atom’s weakened electron attraction. Once the shared charge center of shared electron reaches 0.58 of the distance between Be and S, will the phase be unstable. Moreover, the broadened anti-bonding state and reduced bonding state display that tetrahedral Be-S covalent bonds are weakened. And then, the ZB structure is destroyed and rebuilt to RS structure. Furthermore, changes of covalent bond would cause evident variation of elastic constants and shears on {1 0 0} and {1 1 0} planes.