Magnetic thin film materials tailored by ion irradiation

In recent years the tailoring of magnetic properties by means of ion irradiation techniques has become fashionable.
Since the magnetic properties of multilayers depend sensitively on the mutual interfaces a modification of these interfaces by ion irradiation leads to a local modification of the magnetic anisotropy, the exchange bias or the interlayer exchange coupling [1,2]. Also structural phase transitions can be induced by ion irradiation. If these are accompanied by magnetic phase transformations ferromagnetic regions can immediately be written with a focused ion beam. In addition to pure radiation effects also doping effects can be exploited to achieve a pure magnetic patterning. Finally ion erosion of semiconductor substrates can be used as periodically modulated substrates which modify the magnetic anisotropies of subsequently deposited magnetic films.
Examples of all different approaches will be presented in order to demonstrate the large viability of ion beam technology to tailor magnetic materials.
Refs.: [1] J. Fassbender, D. Ravelosona,Y. Samson, J. Phys. D 37, R179 (2004). [2] J. Fassbender, J. McCord, J. Magn. Magn. Mater. 320, 579 (2008).