Contact hyperfine field at Fe nuclei from density functional calculations

Abstract

The hyperfine field is an important probe of the magnetism of solids, yet its calculation from the first principles in the compounds of $3d$ metals proved to be difficult. For iron we circumvent this problem by calculating the spin magnetic moments of the $3d$ electrons and the valence $4s$ electrons and express the contact hyperfine field as their linear combination. After adding the contributions of the on-site interaction of the nuclear spin with the orbital and spin moment of the $3d$ electrons, the coefficients of the linear combination are calculated by comparison with the hyperfine field experimentally determined in a number of iron compounds. The method brings the theoretical contact fields within $\ensuremath{\sim}1\text{ }\text{T}$ of the values deduced from experiment.