Domain observations of Fe and Co based amorphous wires

Domain observations were made on Fe- and Co-based amorphous magnetic wires that exhibit a large Barkhausen discontinuity during flux reversal. Domain patterns observed on the wire surface were compared with those found on a polished section through the center of the wire. It was found that the Fe-based wire consists of a shell and core region with a third region between them. This fairly thick transition region made up of domains at an angle of about 45 degrees to the wire axis lacks the closure domains of the previous model. The Co-based wire does not have a clear core and shell domain structure. The center of the wire has a classic domain structure expected of uniaxial anisotropy with the easy axis normal to the wire axis. When a model for the residual stress quenched-in during cooling of large Fe bars is applied to the wire, the expected anisotropy is consistent with the domain patterns in the Fe-based wire.<
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