Eur. Phys. J. B (2014) 87: 268
https://doi.org/10.1140/epjb/e2014-50521-6

Regular Article

Ab initio calculations of B₂ type RHg (R = Ce, Pr, Eu and Gd) intermetallic compounds

¹ Department of Physics, Govt. M.L.B. Girls P.G. Autonomous College, 462002 Bhopal, India
² Department of Physics, Barkatullah University, 462026 Bhopal, India

^a e-mail: gita_pagare@yahoo.co.in

Received: 2 August 2014
Received in final form: 27 September 2014
Published online: 10 November 2014

Abstract

Spin polarized ab initio calculations have been carried out to study the structural, electronic, elastic and thermal properties of RHg (R = Ce, Pr, Eu and Gd) intermetallic compounds in B₂ structure. The calculations have been performed by using both generalized gradient approximation (GGA) and local spin density approximation (LSDA). The calculated value of lattice constant (a₀) for these compounds with GGA is in better agreement with the experimental data than those with LSDA. Bulk modulus (B), first-order pressure derivative of bulk modulus and magnetic moment (μ_B) are also presented. The energy band structure and electron density of states show the occupancy of 4f states for light as well as heavy rare earth atom. The elastic constants are predicted from which all the related mechanical properties like Poisson’s ratio (σ), Young’s modulus (E), shear modulus (G_H) and anisotropy factor (A) are calculated. The ductility or brittleness of these compounds is predicted from Pugh’s rule (B/G_H) and Cauchy pressure (C₁₂ − C₄₄). The Debye temperature (θ_D) is estimated from the average sound velocity, which have not been calculated and measured yet.