Elastic and electronic properties of YNi2B2C under pressure from first principles

The elastic and electronic structure properties of YNi2B2C under pressure are investigated by performing the generalized gradient approximation (GGA) and local density approximation (LDA) correction scheme in the frame of density functional theory (DFT). The pressure dependences of the normalized lattice parameters a/a(0) and c/c(0), the ratio c/a, and the normalized primitive volume V/V-0 of YNi2B2C are also obtained. The lattice constants and bulk modulus obtained are in agreement with the available experimental and other theoretical data. We have also studied the pressure dependences of elastic properties. It is found that, as pressure increases, the elastic constants C-11, C-33, C-66, C-12, and C-13 increase, the variation of elastic constant C-44 is not obvious. Moreover, our compressional and shear wave velocities V-L= 6.99 km/s and V-S=3.67 km/s as well as the Debye temperature Theta =549.7 K at 0 GPa compare favorably with the available experimental data. The pressure dependences of band structures, energy gap and density of states are also investigated. (C) 2011 Elsevier B.V. All rights reserved.