Tuning magnetic properties locally by ion irradiation and implantation

Recently it has been demonstrated that ion irradiation of ultrathin magnetic films and multilayer structures is a versatile tool to modify the magnetic properties of these systems in laterally confined areas [1–3]. In most cases the modification of the magnetic anisotropy or the different exchange coupling contributions present in multilayered films are due to a post deposition modification of the interface structure. Depending on the enthalpy of mixing light ion irradiation may result in a roughening or a sharpening of the interface on the atomic level. Due to the local nature of the ion-solid interaction these modifications can be restricted to confined areas resulting in magnetically patterned films without a modification of the surface topography.
An alternative route to ion-driven magnetic nanostructures relies on ion implantation. By doping magnetic thin films in a percentage range with Cr or rare earth transition metals either the Curie temperature [4] or the magnetic damping behavior [5] can be adjusted. In combination with focused ion beam techniques magnetic nanostructures can be written directly into the film structure.
In the presentation I will review the current status of these investigations with respect to magnetic nanostructure formation.

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[3] J. McCord, T. Gemming, L. Schultz, J. Fassbender, M. O. Liedke, M. Frommberger, E. Quandt, Appl. Phys. Lett. 86, 162502 (2005).
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