Substrate-orientation dependence on structure and magnetic properties of MnAs epitaxial layers

Ferromagnetic MnAs layers were grown on (001), (111)A, and (111)B GaAs substrates by molecular-beam epitaxy at substrate temperatures (T-s) in the range from 150 to 400 degrees C. The crystal structure of the MnAs was NiAs type and its orientation was found to change depending on the substrate, (<(1)over bar 101>) for the (001) GaAs substrate and (0001) for the (111)A and (111)B substrates at T-s between 300 and 400 degrees C. Polar magneto-optical Kerr-effect measurement demonstrated a crystal-orientation dependence of Kerr rotation and Kerr ellipticity spectra of the MnAs epitaxial layers.