Dipolar effects in multilayers with interface roughness

Abstract

We present calculations of the dipolar contribution of magnetic coupling between two slabs with rough interfaces. In absence of roughness the dipolar coupling between two perfectly flat infinite planes vanishes but in the presence of topographical inhomogenities the magnetostatic coupling arising from surface magnetic dipoles created by roughness may originate a non-negligible coupling. We developed an analytical model that lead us to consider different interfaces topologies and plane sizes. We show that, depending on the considered roughness and dimensions of the planes, the magnetostatic coupling gives rise to ferromagnetic or antiferromagnetic coupling. We also analyze non-in-plane magnetic configurations and find under suitable conditions that two planes can magnetically couple with one of them pointing its magnetizations out of plane.