Interactions Between Magnetic Layers Lying Between Soft Boundary Layers

Analytic expressions are derived in the 2D frequency-domain for the interaction between magnetized layers that lie between two sheets of soft magnetic material. For example, in writing and reading with perpendicular magnetic recording, a multilayer `hard' magnetic medium lies between the soft magnetic underlayer (SUL) of the medium and the soft structures (including shields) that form the read and write heads. The expression for the interaction between different layers is an extension of earlier work, however the derivation of the self-interaction of a single layer is novel as is the translation of these interactions into tensor form in Cartesian coordinates suitable for micromagnetic modeling.