Hyperfine fields of impurities in ferromagnets

Abstract

Due to the development of Green's function methods the calculation of hyperfine fields of impurities in ferromagnets has become feasible in the last years. We present the result of recent calculations for sp- and d-impurities and their nearest neighbours in Fe. The calculations are based on density functional theory; the potentials of both the impurity and the neighboring host atoms are determined self-consistently. For not too heavy impurities ( Z ≤ 50) the calculations well produce the observed trend of hyperfine fields. We discuss the strong correlation between the local magnetic moment of magnetic impurities and the hyperfine field, observed experimentally, in the light of the calculations. For sp-impurities the so-called systematic behavior of the hyperfine field with increasing Z is explained in terms of the bonding properties between impurity s and host d orbitals.