Long-range magnetic reconstruction of ferromagnetic films with diffused interfaces

Two models of the magnetic structure of a ferromagnetic film deposited on a substrate are developed, with a view to explaining the reduced moment of Fe on GaAs. In the first, spin canting induced by antiferromagnetic exchange in the interface layer falls off rapidly in the interior of the ferromagnet, the characteristic distance being the size of the reconstructed magnetic unit cell in the interface. In the second, random anisotropy in the interface layer induces weakly pinned fluctuations of the magnetization which penetrate to a distance of order the domain wall width, approximately 100 Å.