First-principles investigation of structural, elastic, electronic and thermodynamic properties of strongly correlated ternary system: The DFT plus U approach

Abstract

The elastic, thermodynamic and electronic properties of rhombohedra SiFe2O4 spinel-type are investigated using generalized gradient approximation (GGA) and local density approximation (LDA) approach. The results obtained confirmed the failure of bare DFT to produce the fundamental bandgap of strongly correlated systems. By incorporating the Hubbard correction term (U) on Fe 3d electron, the calculated bandgap using GGA + U was found to be 3.86 eV and this value is comparable with experimental data. The Pugh's ratio and Cauchy pressure values demonstrate the ductility nature of SiFe2O4 spinel. The temperature variation with thermodynamic properties descript the stability of SiFe2O4 spinel. The heat capacity at constant volume increases sharply with temperature and tends to the Dulong-Petit limit at high temperature. The reported value of the bandgap lies within near-ultraviolet (UV) wavelength, revealing that SiFe(2)O(4)spinel-type material may be useful for the photo electrochemical cell of water splitting, flat-panel displays and other optoelectronic applications.