Structural, electronic, elastic, vibrational and thermodynamic properties of U3Si2: A comprehensive study using DFT

摘要

Uranium silicide compound is a promising candidate as low enriched uranium nuclear fuel in light water reactors. Here we report a comprehensive study on structural, electronic, elastic, vibrational and thermodynamic properties of U3Si2 using plane wave based density functional theory. The electron-ion interaction and exchange-correlation energy terms have been described by projected-augmented wave method and generalized gradient approximation scheme, respectively. The relativistic corrections to the total energy have been accounted by incorporating the spin-orbit interactions in the total energy calculations. The results showed good agreement between the experimental and theoretical lattice parameters. The electronic structure of U3Si2 compound suggests significant contribution from the 5f and 3p orbitals of U and Si atoms at the Fermi energy level, respectively. The formation energy (DfH) of U3Si2 at 0 K, after zero point energy correction, have been estimated to be -37.40 kJ/mol. Elastic property calculation of U3Si2 showed mechanical stability and anisotropy at ambient pressure. In addition, the phonon calculation showed that U3Si2 is dynamically unstable. The temperature dependent thermodynamic properties of U3Si2 have also been evaluated using the phonon density of states. (C) 2017 Elsevier B.V. All rights reserved.