Influence of the domain structure on the microwave permeability of soft magnetic films and multilayers

Dynamic permeability measurements of soft magnetic films are performed and their corresponding domain configurations are observed with a Kerr effect microscope. Measurable discrepancies can be observed between the effective permeabilities of layers of different macroscopic sizes and in layered structures. These effects can be associated with the presence of a domain configuration at the edges of the sample. A phenomenological method is proposed to describe these discrepancies. It is supposed that a region at the edge of the sample exhibits a perturbed microwave permeability with lower frequency signals. These outcomes have consequences on the conception of devices using high permeability layers.