Density of States of Rare-earth Permanent Magnet Nd₂Fe₁₄B Using Spin-orbit Coupling

The electronic structures of Nd₂Fe₁₄B are calculated using first-principles fullpotential linearized augmented plane wave (FPLAPW) method. We study the effect of considering the spin–orbit coupling and Coulomb correlations in the Nd₂Fe₁₄B on the magnetic properties and the electronic structure. Results are presented for total density of states (DOS) as well as the site-projected partial density of states (PDOS), the spin magnetic moment of Fe at each of the six in-equivalent transition-metal sites and charge-spin density maps. The total spin-magnetic moments and the average Fe moment are in a good agreement with the values deduced from the neutron scattering experiment and the LDA + U + SO scheme is used. The spin-polarized calculations, excluding the Hubbard and SO interaction, resulted in the total spin magnetic moment is 46.6 μB compared to the experimental values 34.63 μB to the value of 39.6 μB we obtained using LDA+U scheme without Spin-Orbit coupling(SO). But using LDA+U +SO the total spin magnetic moment is 37.6. Including the spin-orbit coupling are necessary for getting a better agreement with experimental data. The charge density map and the spin density maps are calculated on the basal and (110) plane of the tetragonal cell.