Calculation of the transferred hyperfine field (volume overlap) contribution on nonmagnetic impurities in Fe and the Heusler alloys

Abstract

The transferred hyperfine fields (hff) at 4sp and 5sp solute atoms in Fe and the sp sites of the Heusler alloys have been calculated using a volume overlap model. The main difference between this and previous calculations is that the host wavefunction in the solid is represented by an orbital that is simulated from band calculations. The contributions from 2nn and 3nn atoms are also included. The calculated transferred hff values are compared to the hff contributions obtained by substracting the hff due to the host s conduction electron polarization from measured hff values. For the 4sp and 5sp impurities in Fe the calculated transferred hff contributions agree excellently with those obtained from the measured hff. The experimental data for sp impurities at the Z site of Heusler alloys is less complete than that for an Fe host, but again the calculated transferred hyperfine fields agree satisfactorily with those deduced from the measured values. Since for the Heusler alloys there are no arbitrary procedures or parameters relative to the Fe data, the agreement between the calculated and experimental values gives strong evidence in support of the volume overlap model.