Systematics of elastic and thermodynamic properties of super-hardness cubic boron nitride under high pressure

• Published in: Diamond and related materials 2008, Vol.17 (1), p.1-6
• Main Authors: Dong Guo, Yun, Yang, Xiang Dong, Li, Xi BO, Song, Xiao Shu, Cheng, Xin Lu
• Format: Article
• Language: English
• Subjects: Ab initio calculations; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; c–BN; Elastic of properties; Elasticity, elastic constants; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; High pressure; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermodynamic properties
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2007.09.006

The elastic constants of cubic boron nitride (c–BN) are calculated by the first-principles method at ambient condition. The dependence of the elastic constants, the bulk modulus B, and the shear modulus G on the applied pressure are presented. The calculated results are in good agreement with the comparable experimental and theoretical values. The deviation from the Cauchy relation and the elastic anisotropy are investigated. The normalized elastic constants c ij ′ are introduced to investigate elasticity of c–BN in more detail. Moreover, the thermodynamic properties (Debye temperature, melting temperature) and sound velocity have been investigated under high pressure for the first time.