MOMENT CANTING IN METALLIC-GLASS RIBBONS USING SPATIALLY-RESOLVED MOSSBAUER-SPECTROSCOPY

Room temperature Fe-57 Mossbauer spectra of a field-annealed metallic glass of composition Fe78B13Si9 were recorded at ten different 500 mu m diameter locations on the ribbon, and compared with spectra obtained using conventional 1 cm diameter Mossbauer source. Deviations of up t o +/- 1.5 % were observed in the difference spectra, indicating signif icant changes in the directions of the hyperfine fields at the Fe nucl ei. Electron microprobe analysis showed that the iron composition of t he ribbed varies by less than 0.3 at. %, and that these small variatio ns are not correlated with the Mossbauer results. The Mossbauer data s how that as well as the possible atomic-scale non-collinear spin struc ture, changes to the distribution of moment directions occur on a leng th scale of hundreds of microns.