Theoretical investigations on the structural, elastic and electronic properties of binary Beryllides under pressure

摘要

Beryllides (Be12Ti) are expected to be used as the advanced neutron multiplier in the DEMO blanket because of their peculiar properties. In this paper the structural, elastic, and electronic properties of Be12Ti under high pressure are studied through first-principle calculations based on pseudopotential plane-wave density functional theory (DFT) within the generalized gradient approximation (GGA). The calculated lattice parameters are in good agreement with experimental data and the calculated elastic constants of Be12Ti increase monotonically with increasing pressure, demonstrating that Be12Ti satisfies the mechanical stability criteria under applied pressure. Related mechanical properties such as bulk modulus (B), shear modulus (G), Young's modulus (E), and Poisson's ratio (v) are also studied for polycrystalline Be12Ti. The calculated B/G value shows that Be12Ti behaves in a ductile manner, and high pressure can significantly improve the ductility of Be12Ti. Additionally, the electronic properties of Be12Ti under several different pressures are successfully calculated and discussed. (C) 2015 Elsevier B.V. All rights reserved.