Observation of magnetic domain structures in epitaxial MnAs film on GaAs(001) with temperature hysteresis

Abstract

The saturation magnetization of MnAs films epitaxially grown on GaAs(001) substrates exhibited temperature hysteresis in the temperature range of 10-45 degrees C. We investigated the cause of the temperature hysteresis using temperature- and field-controlled magnetic force microscopy (MFM). The MFM results showed that inside the ferromagnetic alpha-MnAs stripes of the film at 30 degrees C, 180 degrees domains were formed during cooling but a single domain state was developed during heating. Despite the cooling procedure, a single domain state was found inside the alpha-MnAs stripes when a magnetic field of 800 Oe was applied. From these results, the spontaneous magnetization of the alpha-MnAs phase was ascribed to the temperature hysteresis. (C) 2011 American Institute of Physics. [doi:10.1063/1.3564900]