Domain structures in rapidly annealed Fe7Co18B14Si1

Amorphous ribbons of Metglas 2605CO (Fe₆₇Co₁₈B₁₄Si₁) have been rapidly annealed in a transverse (i.e. at right angles to the ribbon axis) magnetic field at temperatures close to the Curie point. Stress is not totally relieved but the domain structure largely consists of straight walls lying parallel to the applied field direction. More interesting is the presence of finely spaced walls running perpendicular to the direction of the magnetization vector in the main domains. These wall features indicate considerable dispersion of the magnetization, a conclusion borne out by their behaviour in externally applied fields both parallel and perpendicular to the ribbon axis.