Growth and magnetoresistance of epitaxial metallic MnAs/NiAs/MnAs trilayers on GaAs (0 0 1) substrates

Molecular beam epitaxial growth and magnetic properties of fully epitaxial metallic MnAs/NiAs/MnAs trilayers on GaAs (001) substrates are reported. Cross-sectional TEM lattice images indicate that the heterointerfaces of the metallic trilayers were atomically abrupt. Magnetoresistance (MR) measurements of a MnAs View the MathML source heterostructure were carried out in current-in-plane geometry, and we observed unique MR loops, in which the sign of MR was changed from negative to positive depending on temperature. The MR ratio was 0.28% at View the MathML source and it decreased with increasing temperature, but it remained (0.06%) at room temperature.