Edge-curling-wall discontinuities and interactions with Bloch walls in easy-axis Permalloy

Laminations of soft-magnetic and nonmagnetic films, which meet the criteria for easy-axis state, have edge-curling walls instead of the triangular closure domains of single sheets. A laser magnetooptic microscope has been used to image and model two types of edge-curling wall discontinuities that are induced by geometry in finite elements. One is a sectored-vortex discontinuity in a single-domain state that was not previously predicted. In addition, laminates with Permalloy layers on the order of 1- mu m thick are usually divided into easy-axis domains by 180 degrees Bloch walls. Several types of interaction of a Bloch wall with an edge-curling wall are described. The existence of coupled (top and bottom layers) single-domain states in two-magnetic-layer elements is confirmed.< >