2D wall profiles in exchange coupled bilayers

Two-dimensional wall configurations in exchange coupled bilayers are calculated using numerical micromagnetic simulations. Starting with a 180 degrees domain arrangement in zero field, full saturation is, under hard axis field, only reached for field values large with respect to the anisotropy field, due to the nucleation of 360 degrees walls. Their collapse field is computed versus the magnitude of the interlayer exchange coupling. A novel hysteresis mechanism, specifically for large coupling constants and involving superposed 360 degrees walls, is described.<
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