Epitaxial metallic nanostructures on GaAs

High quality metal/insulator heterostructures are grown epitaxially on semi conductor GaAs(100) substrates using appropriate MgO(100) buffer layers. Tw o model systems are described: Fe/MgO/Fe trilayers, that are used to fabric ate and study epitaxial magnetic tunnel junctions, and W(100) films, which exhibit ballistic transport properties with high electron mobility. In both cases the quality of the crystalline structure as well as the interfaces a t the atomic level are related to the observed magnetic and transport prope rties. (C) 2001 Elsevier Science B.V. All rights reserved.