1^st principle study of Co-Fe alloy structural and magnetic properties

Abstract This study investigates the structural and magnetic properties of cobalt (Co), iron (Fe), and their alloy (CoFe) using first-principles density functional theory (DFT) calculations. Employing the Perdew-Burke-Ernzerhof (PBE) functional and its extension with Hubbard U (PBE+U), the effect of U values on the electronic structure and magnetic properties of these systems is explored. The results show that increasing the U value leads to an enhancement in both lattice parameters and magnetic moments for Fe, Co, and the CoFe alloy. Specifically, BCC CoFe is found to be more energetically stable than HCP CoFe, with BCC CoFe exhibiting higher magnetization values for both Co and Fe atoms. The projected density of states (PDOS) reveals distinct shifts in the Co and Fe 3d bands depending on the U value. Overall, this work provides insights into the behaviour of CoFe alloys, particularly in relation to their structural stability and magnetism, offering valuable guidance for future theoretical and experimental investigations in magnetic materials.