Domain splitting in thin films with in-plane anisotropy

Splitting of magnetic ripple into domains due to an external magnetic field was observed using the defocused electron microscopy method. The tested film was magnetized perpendicularly or parallel to the easy axis of the uniaxial anisotropy, and both the magnetic field direction and the anisotropy axis lay in the film plane. Splitting of the ripple into 1 μm domains was mainly reversible until the value of ripple amplitude reached 0.5 rad. Movements of the Néel walls and Néel-Bloch-Néel transformation of the domain walls were the main irreversible phenomena which led to hysteresis. Domain splitting of the ripple is properly described only by a Riedel model which includes the interactions between cores and tails of the periodically arranged Néel walls.