Magnetic structure of epitaxially grown MnAs on GaAs(001)

We investigate in detail the occurrence of magnetic domains in epitaxially grown MnAs films on GaAs(001) by magnetic force microscopy (MFM). MnAs laye rs exhibit in their demagnetized state a very complex magnetic domain struc ture. High resolution MFM images reveal detailed information on the domain wall. Additionally, we imaged magnetic domains in the dependence on the app lied magnetic field. This detailed investigation gives new insight into the correlation between film topography and magnetic domain structures. System atic magnetization measurements in-plane and out-of-plane have shown high a nisotropy in our films. The out-of-plane magnetization determined as a func tion of the applied field reveals that the direction of the magnetic moment s in the domain walls are out-of-plane, thus the domain walls are determine d as 180 degrees Bloch type. (C) 2000 American Institute of Physics. [S0021 -8979(00)07617-9].