Magneto-optical investigation of the domain structure of amorphous Fe80B20 alloys

In amorphous Fe80B20-alloys the domain structure is investigated by means of the longitudinal magneto-optical Kerr effect. The domain pattern is found to be related closely to the spatial distribution of compressive and dilatational internal stresses. A quantitative analysis of the field dependence of the width of the domains leads to an effective anisotropy energy of Ksub(eff) 2 x 103 J/m3, and a specific Bloch wall energy of γsub(B) 0.6 x 10-3 J/m2 = 0.6 erg/cm2. The amplitude of compressive stresses is found to be approximately 1 N/m2 corresponding to 2 permille of the shear modulus. (author)