MnAs growth in molecular beam epitaxy and its magnetic properties

The effects of the growth temperature on the structural and magnetic properties of MnAs has been studied. The results from x-ray diffraction, transmission electron microscopy, and magnetic property measurements consistently showed that the optimum substrate temperature for continuous epitaxial growth should be low, at around 300 .deg. C. The MnAs films divided into agglomerated separated grains at high substrate temperatures, with a discontinuous polycrystalline nature. The low-temperature-grown MnAs film showed a strong uniaxial magnetic anisotropy as also observed by a W-shape planar Hall resistance. This anisotropy was shown to have strong correlation with the surface reconstruction on the GaAs substrate