First-principles calculations to investigate structural, electronic, optical and mechanical properties of Mg-doped CaMoO3 cubic perovskites for fuel cell applications

Abstract

The structural, optical, electrical, and mechanical characteristics of pure and Mg-doped CaMoO3 perovskites materials were examined in a first-principle research based on density functional theory. The current study employs the PBE (Perdew Burke-Ernzerhof) exchange co-relational functional of GGA along with the USP (Ultra-soft Pseudo-potential) plan wave and CASTEP (Cambridge Serial Total Energy Package) code (Generalized Gradients Approximation). The impact of Mg on the structural, optical, electrical, and mechanical characteristics of CaMoO3 is examined using a generalized gradient approximation (GGA) and an ultra-soft pseudo-potential. After adding Mg to the Mo site, it is discovered that the band gap of CaMoO3 with Mg doping has significantly decreased. According to the DFT investigation, Mg is an ideal material to lower CaMoO3's band gap. The volume of crystal cells similarly fell from 61.99 to 57.94 A3 with the addition of Mg due to the difference in ionic radii between Mo and Mg. The incorporation of Mg in CaMoO3 results in a highly stable material, which is demonstrated by the as-calculated negative cohesive energy values, according to the as-obtained elastic constants (Cij). The elastic constants, ductility, elastic moduli, and elastic anisotropy of pure and Mg-doped CaMoO3 cubic perovskite materials have also been investigated. These findings demonstrate that Mg doping successfully raises CaMoO3's elastic moduli. The Mg-doped CaMoO3 material transforms from brittle to ductile due to the introduction of Mg at sites of Mo, as computed Pugh's ratio is dropped from 2.499 to 1.995 and Poisson's ratio from 0.323 to 0.285. For both pure and Mg-doped CaMoO3, band topologies, densities of states, and charge density re-locations are also expected.