サブミクロンサイズ強磁性細線における180°対向磁壁の磁気構造  [in Japanese] Magnetic Structure of the 180° Head-on-Head Domain Wall Observed in Submicron-Size Ferromagnetic Wires  [in Japanese]

The micromagnetic structure of the 180° domain wall in submicron-size ferromagnetic Co wires was investigated by means of magnetic force microscopy. The wall width δ (〜μm) observed in Co write is much larger than that observed in Co films of the same thickness. From micromagnetic calculation using the Landau-Lifshitz-Gilbert (LLG) equation, the magnetic structure of the 180° wall is expected to be a large vortex accompanied by a magnetic ripple structure. This complicated 180° wall is formed to suppress the demagnetizing energy due to a head-on-head configuration of the magnetization, which results in a micron-scale-wide transition area of the wall. The wire-width dependence of the 180° wall width obtained by micromagnetic calculation is almost consistent with that measured from the magnetic force micrograph.