Epitaxial MnGa/(Mn,Ga,As)/MnGa trilayers: Growth and magnetic properties

Abstract
Epitaxial ferromagnet/semiconductor/ferromagnet sandwiches with the nominal structure δ Mn60Ga40/GaAs/δ Mn54Ga46 have been grown on GaAs(001) by molecular beam epitaxy, with spacer layer thicknesses ranging from 2 to 19 monolayers (ML) GaAs nominally. A strong antiferromagnetic coupling field μ0Hs=−12 to −39 mT at room temperature is observed for spacer layers of 4–14 ML GaAs nominally, a weaker ferromagnetic coupling of +1 to +7 mT exists outside of this thickness region. Magnetic contamination of the spacer layer and the inclusion of antiferromagnetic Mn2As cannot be ruled out.