Theoretical study of hyperfine fields at diluted s–p, noble, and nd impurities in ferromagnetic compounds GdX (X=Zn, Cd)

• Published in: Journal of applied physics 2000-05, Vol.87 (9), p.4882-4884
• Main Authors: de Oliveira, A. L., Tovar Costa, M. V., de Oliveira, N. A., Troper, A.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.373190

The hyperfine fields at nd (n=3,4,5) impurities and at noble impurities diluted in ferromagnetic compounds GdX (X=Zn, Cd) are discussed in the framework of a two center model. In these systems it is observed that all impurities enter substitutionally at the “nonmagnetic” X lattice site, thus creating a strong local charge perturbation. In our model, one calculates the local magnetic moment in the charge perturbed conduction band at the origin. The magnetization of the s–p conduction band arises from the Gd 4f moments. Then one obtains the conduction electron polarization contribution to the hyperfine field. The transition (and noble) impurities also create an Anderson–Moriya d resonance in the strongly perturbed Slater–Koster local density of states at the origin, thus originating an additional local moment and thereby a core polarization contribution to the magnetic hyperfine field. The self-consistently calculated hyperfine fields are in quite good agreement with available experimental data.