Surface magnetic microstructure of melt-spun magnetic ribbons

Scanning electron microscopy with polarization analysis (SEMPA) and photon-excited spin polarized secondary electron spectroscopy have been used to study respectively the lateral variations and depth profiles of the surface magnetic microstructure of as-cast amorphous melt-spun Fe80B20 ribbons. The 5 mu m resolution SEMPA images showed very similar complex domain patterns for both remanent and field-on states, and spot mode hysteresis loops showed significant differences across the sample. These data are consistent with a very wide distribution of strain-induced anisotropy fields. Energy resolved hysteresis loops (ERHL) measured using photoemitted 1 and 20 eV secondary electrons showed clear differences in form, attributable to changes in probing depth. A unidirectional anisotropy found in the 20 eV ERHL is linked tentatively to the inhomogeneities revealed by SEMPA. (C) 1997 American Institute of Physics.