Theoretical investigation on the high-pressure structural transition and thermodynamic properties of cadmium oxide

¹ Department of Physics, Nanyang Normal University - Nanyang 473061, China
² Institute of Atomic and Molecular Physics, Sichuan University - Chengdu 610065, China
³ International Centre for Materials Physics, Academia Sinice - Shenyang 110016, China
⁴ Department of Physics, Ludong University - Yantai 264025, China

^a lucheng@nynu.edu.cn

Received: 22 May 2010
Accepted: 24 June 2010

Abstract

A theoretical investigation on the structural and thermodynamic properties of CdO under high pressure is performed by employing the pseudopotential plane-wave method in the framework of the density functional theory. Some structural parameters of CdO in both B1 and B2 phases are reported. According to the third-order Birch-Murnaghan equation of states, the transition pressure P_t of CdO from the B1 structure to the B2 structure is determined. The calculated results are found to be in good agreement with the available experimental data and theoretical values. Based on the quasi-harmonic Debye model, the Debye temperature of CdO under high pressure is derived from the average sound velocity. This is a quantitative theoretical prediction of the elastic and thermodynamic properties of CdO and it still awaits experimental confirmation.