Structural, Electronic and Elastic Properties of Be 2 B Compound. Venu Mankad, Sanjeev K Gupta, Prafulla K Jha Department of Physics, Bhavnagar University, Bhavnagar, Gujarat- 364022. Email: pkj@bhavuni.edu Abstract. A detailed theoretical study of structural, electronic and elastic properties of Be 2 B compound is presented by performing ab-initio calculations based on density-functional theory using the ABINIT. The calculated value of lattice constant and bulk modulus are compared with the available experimental and other theoretical data and agree reasonably well. The calculated elastic constants satisfy the mechanical stability criteria. Zener anisotropy factor (A), Poisson’s ratio (v), Young’s modulus (E), shear modulus (C’), elastic wave velocities for Be 2 B compound is also reported. Keywords: Electronic band structure, Elastic properties, Lattice dynamics, Ab-initio calculation. PACS: 61.50.Ks, 63.20.Dj, 63.20.Ry INTRODUCTION In recent years Beryllium semi-boride (Be 2 B) has attracted great attention as a potential superconductor [1]. Theoretical prediction of changes in the electrophysical properties of Be 2 B caused by electron, isoelectron or hole doping as a result of partial substitution of beryllium by Al, Mg, and Na, respectively, is reported in [1]. The potential of this system for materials science is substantially dependent on their mechanical properties. Be2B crystallizes in cubic crystal lattice (CaF 2 -type space group: Fm3m ) [2]. The present paper reports a systematic study on the first principles study of elastic and electronic properties of Be2B compounds. METHOD OF CALCULATION In this article, all calculations were performed within the framework of DFT using a basis set consisting of plane waves, as implemented in the ABINIT [3]. The electron–ion interactions were described by pseudopotentials and electron exchange and correlation energies were calculated with the gradient-corrected functionals in the form of the generalized-gradient approximation (GGA) by Perdew and Wang [4]. The kinetic energy cutoff 19 Ha of the plane wave basis was used throughout and the Brillouin zone was sampled with a 8x8x8 grid of special k-points as proposed by Monkhorst and Pack [5]. RESULT AND DISCUSSION The equilibrium lattice constant, bulk modulus, and its total energy of the crystal are calculated at different volumes by means of Murnaghan’s equation of state [6]. The total energy versus lattice constant graph is presented in Fig.1. 8.2 8.4 8.6 8.8 9.0 9.2 -151.25 -151.20 -151.15 -151.10 -151.05 -151.00 -150.95 -150.90 Total energy(eV) Lattice constant(Bohr) Be 2 B Rocksalt-Phase Figure1. Energy versus lattice parameter curve The present value of lattice constant for rock salt (B1) structure of Be 2 B compound is in good agreement with experimental and other theoretical values (TableI) The present value of optimized lattice parameter for Be 2 B is 1.47 % higher than the available experimental result [6]. It is worth noting that C 11 coefficients are much higher than C 44 ones (Table-I). This indicates that the Be 2 B in cubic structure is less resistant to the applied shear. The traditional mechanical stability conditions on the elastic constants are satisfied at zero pressure. The calculated shear modulus ,Young’s modulus, Poisson’s ratio, Shear wave modulus and Anisotropic factor is presented in Table-II.The present value of Anisotropic factor suggests that the present Be 2 B is less anisotropic compound . Solid State Physics, Proceedings of the 55th DAE Solid State Physics Symposium 2010 AIP Conf. Proc. 1349, 863-864 (2011); doi: 10.1063/1.3606131 © 2011 American Institute of Physics 978-0-7354-0905-7/$30.00 863 Downloaded 12 Jul 2011 to 117.211.84.58. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions