MnAs growth in molecular beam epitaxy and its magnetic properties

The effect of the growth temperature oil 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 degreesC. The MnAs films divided into agglomerated separate 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 vas shown to have strong correlation with the surface reconstruction oil the GaAs substrate.