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Supersaturated Fe-Pd solid solutions were prepared by mechanical alloying. X-ray diffractometry showed that the as-milled alloys were bcc from 0-26 at. % Pd. Saturation magnetization measurements and Mössbauer spectrometry measurements were performed on these powders. Consistent interpretations of both sets of measurements were possible if the magnetic moment at the Pd atom was 0.35 B and constant, and if the magnetic moments at Fe atoms were enhanced by neighboring Pd atoms in a way similar to the effects of Ni.

The angular dependence of surface magnetic Barkhausen noise ͑MBN͒ with flux densities up to 1.7 T on eight different samples of oriented 3% Si-Fe steel laminate was investigated. On two of the samples encircle MBN measurements were performed. MBN energy values were obtained by integrating the square of the MBN voltage signal with respect to time. The angular variation of the MBN energy signal was modeled by considering anisotropic internal fields that moderate 180°d omain wall motion and the local eddy current field interactions between spatially correlated Barkhausen events. The eddy current field interactions arising between 180°domain walls that lie along the sample's primary easy axis direction were represented by a parameter, ␣Ј. ␣Ј had a cos angular dependence where is the angle of the applied sweep field with respect to the sample rolling direction. The angular averaged MBN energy signal, ͗Energy͘, was evaluated and compared with core losses measured using the standard Epstein technique at 1.5 T. Surface MBN measurements on samples with higher ͗Energy͘ demonstrated lower core loss. This was associated with a larger proportion of microscopic eddy currents generated parallel to the sample plane which were, therefore, uncoupled from macroscopic eddy currents generated by the bulk magnetization of the sample. Larger surface ͗Energy͘ signals were identified with a finer domain wall structure. For samples with a nonzero ␣Ј, the core loss was observed to decrease with increasing ␣Ј magnitude. This was interpreted as a result of a reduction of microscopic eddy currents arising from an increase in interactions between simultaneously moving 180°domain walls.

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We present results on Barkhausen noise power in grain oriented 3% Si–Fe samples of different quality (power losses). Barkhausen noise is measured at constant values of the magnetic field applied in the rolling direction of the sheet. The measurements indicate a strong correlation between the Barkhausen noise power and total power losses. A model is proposed to interpret the results according to which the Barkhausen noise power is related to the density of pinning centers per unit coercive field, an intrinsic parameter of the material. It is shown that this parameter characterizes the ability of the external field to increase the number of moving walls. The model and the experiment demonstrate that the power losses in grain oriented 3% Si–Fe are improved either by dynamic homogenization of magnetization, or by decreasing the domain wall spacing in static conditions.