Chirality-induced zigzag domain wall in in-plane magnetized ultrathin films

The domain structure in in-plane magnetized Fe/Ni/W(110) films is investigated using spin-polarized low-energy electron microscopy. A novel transition of the domain wall shape from a zigzaglike pattern to straight is observed as a function of the film thickness, which is triggered by the transition of the domain wall type from the out-of-plane chiral wall to the in-plane Néel wall. The contribution of the Dzyaloshinskii–Moriya interaction to the wall energy is proposed to explain the transition of the domain wall shape, which is supported by Monte Carlo simulations.