Growth and magnetic properties of epitaxial MnAs/NiAs/MnAs hetero structures grown on exact GaAs(111)B substrates

摘要

We have investigated the growth, structural characterization and magnetic properties of epitaxial MnAs/NiAs/MnAs heterostructures grown on exact GaAs(111)B substrates by molecular beam epitaxy. Reflection high energy electron diffraction observation during the growth and cross-sectional transmission electron microscopy analysis revealed that the epitaxial orientation of [0001]MnAs//[0001]NiAs//[(1) over bar(1) over bar(1) over bar ]GaAs is maintained throughout the growth with atomically abrupt heterointerfaces. The magnetization loops of the heterostructures show double-step features when the thickness of the NiAs interlayer was more than 8 nm. The magnetic properties, such as the temperature dependence of magnetization, were sensitive to the growth conditions, which mainly results from the crystalline quality of the top MnAs layer. © 2005 Elsevier B.V. All rights reserved.