LOCAL MAGNETIZATION AND HYPERFINE FIELD SYSTEMATICS OF S-P AND NOBLE IMPURITIES IN GD AND NI HOSTS

Magnetic hyperfine data of s-p and noble impurities diluted in ferroma gnetic Gd and Ni hosts are described within a simple model which is an extension on that one of Daniel and Friedel. We also include in the p resent model the effect of next-neighbor perturbation, due to the tran slational invariance break introduced by the impurity. Performing a se lf-consistent calculation of the local magnetic moments at the impurit y site, one obtains the conduction electron polarization (CEP) hyperfi ne field. It is found that the model can explain the different hyperfi ne field trends observed in Gd and Ni hosts, e.g., a remaining negativ e value along the s-p series in the Gd case and a change of sign behav ior in the Ni case. Period effects observed in noble impurities are al so;; discussed and the theoretical calculations are in good agreement with available experimental data. (C) 1997 American Institute of Physi cs.