Current-controlled domain structures in micron-sized magnetic permalloy rods

The discovery of current-controlled domain structures in micron-sized permalloy rods is reported. At zero-applied field, the remanent domain structures of 12 μm × 3 μm rods with a thickness of 40 nm are imaged with magnetic force microscopy and compared to results from micromagnetic simulations. Both studies revealed a stable flux-closure state, which we term the 3-diamond state at remanence. After constant current applications in the order of 10⁷ A/cm², another stable flux-closure state, the 1-diamond domain structure was observed. In this paper, we explain the domain evolution process of the rods as well as the domain structures created under the influence of the local magnetic environment.