Extrinsically controlled spin relaxation in NiFe thin films induced by a periodic scattering potential

The spin relaxation process of thin Ni80Fe20 (Py) films is influenced by introducing a periodic scattering potential using ion beam techniques. These potentials can be created in two ways: (i) by Cr+ implantation into the surface of the Py film, using a lithographically defined mask. (ii) by using nanometer scale periodically modulated substrates (ripple) that change the morphology of the Py film grown on top [2].
The magnetic damping contributions are determined by frequencydependent ferromagnetic resonance measurements using a vector network analyzer. For both sample systems we find several strongly enhanced linewidth peaks over a wide frequency range. By varying the scattering potential, the frequency positions of the damping peaks are preselectable.
This work is supported by DFG grant FA 314/6-1 and SFB 491.
[1] I. Barsukov et al., Phys. Rev. B 84, 140410(R) (2011).
[2] J. Fassbender et al., New Journal of Physics 11, 125002 (2009).