Structural Optimization and the Study of the Electronic, Mechanical, Thermodynamic and Phonon Properties of Mg2sn from First Principle
I. S. Okunzuwa *
Department of Physics, University of Benin, Benin City, Nigeria.
E. Aigbekaen, Eddy
Department of Physics, College of Natural and Applied Sciences, Igbinadion University Okada, Benin City, Nigeria.
T. Philips Chidubem
Department of Physics, University of Benin, Benin City, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
First principles pseudopotential method based on density functional theory is used to investigate the Structural, Mechanical, Phonon, Thermodynamic and Electronic properties of Mg2Sn. The equilibrium properties including lattice constant, bulk modulus, pressure derivative cohesive energy, young modulus, shear modulus were determined. The results obtained were compared with available experimental and other available results. Mg2Sn was found to be brittle in nature with a non-metallic properties as shown by the value of the Cauchy pressure of -4.03. The Phonon dispersion curve of Mg2Sn was obtained utilizing the PBE-GGA exchange-correlation potential as employed in the Vienna Ab-Initio Simulation Package (VASP) computer code. The gap separating the acoustic and the optical branch of the curve was found to be about 50cm-1 at X-point. The thermodynamic properties of the material was investigated in the temperature of 0-800K. At room temperature, the calculated value of the specific heat capacity ( ) is 71.28J/mol which is in good agreement with experimental and other results. Mg2Sn was found to a narrow gap semiconductor with an indirect bandgap of magnitude of 0.175eV.
Keywords: Psuedopotential, phonon, density of state, thermodynamic, plane waves, pseudopotential, density functional theory.