Direct observation of saw-tooth typed domain wall jumps in epitaxial ferromagnetic MnAs film on GaAs(001)

摘要

We report the direct observation of saw-tooth domain wall jumps in epitaxial ferromagnetic MnAs film on GaAs(001) via a magneto-optical Kerr effect microscope. Interestingly, it is found that the saw-tooth domain wall jumps are generated along an easy axis orientation and the saw-tooth angle is nearly constant irrespective of the applied field direction. These observations can be understood on the basis of strong uniaxial anisotropy on the sample plane. The analytical study reveals that the saw-tooth domain wall structure results from competition between the domain wall energy and the dipolar energy.