Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

The magnetic anisotropy of Pt/Co/Pt sandwiches transforms from in-plane to out-of-plane and back as a function of uniform Ga+ ion irradiation fluence [J. Jaworowicz et al., Appl. Phys. Lett. 95 (2009)]. We study the effect of the irradiation on magneto-optical (MO) Kerr spectra between 1 and 5 eV in Pt(5nm)/Co(3.3nm)/Pt(20nm)/Mo(20nm). In the range up to an irradiation fluence of 1e15 ions/cm² the MO amplitudes gradually increase and at 6e15 ions/cm² it falls below that of the non-irradiated sample. The results are explained assuming the model system Pt/PtxCo1-x/Co/PtxCo1-x/Pt which accounts for increased PtCo alloy thicknesses at the interfaces. At 6e15 ions/cm², the reduction in MO amplitudes is explained by the circumstance that a significant part of the sample is ablated and the sandwich reduces to a single alloy layer.