Blending magnetic properties - hybrid magnetic thin films

The control of the effective magnetic anisotropy, saturation magnetization, as well as the dynamic magnetic properties in ferromagnetic thin films is of significant importance for most applications in spin electronics. Usually the magnetic anisotropy, e.g. uniaxial anisotropy or unidirectional anisotropy, in ferromagnetic single or multi-layers is initialized by applying a magnetic field during film deposition or by a magnetic field anneal, which results in an anisotropy aligned along the applied field direction. The saturation magnetization is mainly determined by the film's composition. Whereas anisotropy and saturation magnetization together determine the precessional frequency of the films, the magnetic damping parameter cannot easily be varied in a controlled way.
Here we give a summary on different ways to pattern magnetic films in terms of laterally varying magnetic properties and not by shape patterning [1]. Different samples of anisotropy [1,2], exchange bias [1,3], and saturation magnetization [4] modulated thin films are prepared by local oxidation, introducing local stress variation [5], and local ion irradiation or implantation. The magnetization reversal processes in the two-phase materials exhibit unique features, some of them so far only known from multilayer samples. The main emphasis of the investigations is on the role of magnetic domain formation and domain wall effects in stripe-like magnetic hybrid structures on the overall static and dynamic magnetic properties.
The presented paths of film preparation provide an additional degree of freedom for the tailoring of magnetic properties and functionality of soft-magnetic thin films.