Pairs of Effective Spin Merons in Ferromagnetic Multilayer Elements


Pairs of Effective Spin Merons in Ferromagnetic Multilayer Elements

Wintz, S.; Bunce, C.; Neudert, A.; Körner, M.; Strache, T.; Buhl, M.; Erbe, A.; Gemming, S.; Raabe, J.; Quitmann, C.; Fassbender, J.

We report on pairs of diverging/converging spin vortices in Co/Rh/Ni81Fe19 disks. The lateral magnetization distribution of these effective spin merons [1] is directly imaged by means of element-selective x-ray microscopy. By this method, both the circulation and divergence states of the individual layers are identified as antisymmetric [2] (see Figure 1). Magnetization reversal measurements of corresponding continuous films reveal that biquadratic interlayer exchange coupling is the origin for the formation of such effective meron pairs. Furthermore, the effective meron pair’s three-dimensional magnetic structure is determined via micromagnetic simulations. We find that the perpendicular magnetization component is distributed nonhomogeneously, namely M is partially circulating on a flux-closing torus. This toroidal topology enforces a symmetry break, which ties the core polarities to the divergence configuration. Upon excitation, such topology-induced core stabilization could lead to enhanced maximum amplitudes of steady gyration compared to single layer vortices, as the meron pair’s core switching onset velocity is expected to be higher than that of a single vortex.

  • Lecture (Conference)
    58th Conference on Magnetism and Magnetic Materials (MMM), 04.-08.11.2013, Denver, USA

Permalink: https://www.hzdr.de/publications/Publ-18911
Publ.-Id: 18911