Domain wall motion in perpendicular recording films

The wall motion in films for perpendlcular recording is investigated in terms of the atomic layer model, One-dimensional inhomogeneities of magnetic parameters which may be caused by the film structure can be introduced in the model. As an example fluctuations of the Cr content in Co-Cr films are described by a sine-shaped profile of inhomogeneity. This yields a calculated dependence of the wall coercivity as a function of the profile period which is in good agreement with experimental results of other authors. Taking into account the known formula for demagnetizing fields of stripe domains perpendicular hysteresis loops can be calculated, One example is shown and compared with an experimental loop.