First-principle investigation of stability, magnetic moments, electronic and optical properties of Fe with GGA and GGA+U

The stability of the bcc FM of Fe, the magnetic moments, electronic structure, and optical properties have calculated for the cases of bcc and fcc Fe, for non-magnetic (NM), ferromagnetic (FM), and antiferromagnetic (AFM) states, using the full-potential linearized augmented plane wave method (FP-LAPW) with the generalized gradient approximation (GGA) and GGA+U within the framework of density functional theory (DFT), as implemented in the WIEN2k code. The magnetic moments increase when significant correlations are taken into account. The Density of State (DOS) changes significantly with the FM state but not much with the NM or AFM states, which is consistent with Iota's findings. The optical properties results obtained for the interband dielectric function ε(w), variation in the energy-loss spectrum L(w), absorption coefficient α(w), refractive index n(w), reflectivity R(w), and optical absorption σ(w), are comparable with other studies. Our findings are in good agreement with earlier experimental and theoretical Findings.