We successfully grew epitaxial MnAsGaAs superlattices at various growth temperatures (Tg) with a periodicity of 55 nm using molecular-beam epitaxy and characterized their magnetic and electrical transport properties. Structural analysis shows that the magnetic anisotropy originates from the crystal domain structure of the MnAs layers. The metallic behavior for the sample with Tg =375 °C systematically changed to semiconducting on increasing Tg up to 540 °C. The transport properties of thin single layered MnAs films with a thickness of 20 nm showed the same Tg dependency. These observations indicate that the semiconducting characteristics of MnAsGaAs superlattices are attributable to a radical alteration of the electronic structure of the MnAs layers.
ASJC Scopus subject areas
- Physics and Astronomy(all)