Electrical-transport, magneto-transport and magnetic anisotropy of epitaxially grown MnAs/GaAs hybrid multilayers

We successfully fabricated epitaxial MnAs/GaAs multilayers with a total thickness of 300 nm using molecular beam epitaxy. The periodicity of the samples was varied from 0.5 to 10 nm. All samples exhibited ferromagnetism above room temperature and show semiconductor-like behavior in the temperature range studied. Anisotropy of the magnetic, electrical, and magneto-transport properties was observed for the samples exhibiting a two-fold symmetric crystal structure on sample surface whereas no anisotropy was exhibited for the samples with four-fold symmetry. These results indicate that such anisotropies originate from the structural anisotropy.