Moment canting in metallic glass ribbons using spatially resolved Mossbauer spectroscopy

Room temperature /sup 57/Fe Mossbauer spectra of a field-annealed metallic glass of composition Fe/sub 78/B/sub 13/Si/sub 9/ were recorded at ten different 500 mu m diameter locations on the ribbon, and compared with spectra obtained using a conventional 1 cm diameter Mossbauer source. Deviations of up to +or-1.5% were observed in the difference spectra, indicating significant changes in the directions of the hyperfine fields at the Fe nuclei. Electron microprobe analysis showed that the iron composition of the ribbon varies by less than 0.3 at.%, and that these small variations are not correlated with the Mossbauer results. Mossbauer data show that as well as the possible atomic-scale non-collinear spin structure, changes to the distribution of moment directions occur on a length scale of hundreds of microns.<
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