Effects of magnetization ripple in GdCo amorphous films

A recent study on GdCo amorphous alloy films obtained by RF-sputtering onto glass substrates is reported. The susceptibility has been measured and from the field dependency of the susceptibility the anisotropy constant and the intrinsic stray field of the films have been calculated. In addition to the investigations at the film surface, the film-substrate interface has been investigated in the same way. The anisotropy and stray field at the film-substrate interface deviated strongly from the values at the opposite spot. As a result, the magnetization is expected to be inhomogeneous through the film, leading to ripple effects as known from soft magnetic films. In order to describe these effects, a micromagnetic ripple theory was developed, assuming a one-dimensional variation of the magnetization as well as of the local anisotropy.