New approaches to epitaxy of transition metals and rare earths: Heteroepitaxy on lattice-matched buffer films on semiconductors (invited)

Examples of new approaches to epitaxy of magnetic transition metals and rare earths are described. Epitaxy of bcc Fe on lattice-matched InxGa1−xAs films is accompanied by an interfacial reaction. This is indicative of a more general problem of instability of interfaces between Ni, Fe, Co, and compound semiconductors. Such reactions can be avoided if an intermediate epitaxial film of Ag is interposed between the semiconductor and the Fe. However, this results in long-range coherency strain and tilted epitaxy of Fe. Epitaxial growth of the rare-earth metal Dy onto epitaxial films of LaF3 on GaAs(1̄1̄1̄) is described and the magnetic properties of epitaxial sandwich structures of LaF3/Dy/LaF3 summarized.