Regular Article

Ab initio study of structural, elastic, and electronic properties of Mo_3.46B₁₂ under high pressure

¹ Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Cd. Mex., México, C.P. 04510, Mexico
² Facultad de Ciencias, Universidad Nacional Autónoma de México, Apartado Postal 70-399, Cd. Mex., México, C.P. 04510, Mexico

^a e-mail: rauleg@unam.mx

Received: 13 November 2018
Received in final form: 26 November 2018
Published online: 4 February 2019

Abstract

First-principles calculations are performed to investigate the structural, elastic, and electronic properties of the Mo_3.46B₁₂ under pressure based on the generalized gradient approximation (GGA) proposed by Perdew–Wang (PW91). The initial results show that the optimized lattice parameters at a pressure of zero GPa are in good agreement with the experimental and other theoretical results. The effect of high pressure on the crystal structure reveals that the compression along the c-axis is stronger than along the a-axis. We find that the elastic constants, elastic modulus, hardness, and Debye temperature (θ_D) increase and the Grüneisen parameter (γ) decreases due to stiffening of the crystal structure under pressure. Consequently, the structure is mechanically stable, brittle, and elastically anisotropic. Finally, the density of states at Fermi level N(E_F) decreases under pressure due to decreasing of the B 2p states.