title: Interface Engineering to Create a Strong Spin Filter Contact to Silicon.
abstract: Integrating epitaxial and ferromagnetic Europium Oxide (EuO) directly on silicon is a perfect route to enrich silicon nanotechnology with spin filter functionality. To date, the inherent chemical reactivity between EuO and Si has prevented a heteroepitaxial integration without significant contaminations of the interface with Eu silicides and Si oxides. We present a solution to this long-standing problem by applying two complementary passivation techniques for the reactive EuO/Si interface: (i) an in situ hydrogen-Si (001) passivation and (ii) the application of oxygen-protective Eu monolayers-without using any additional buffer layers. By careful chemical depth profiling of the oxide-semiconductor interface via hard x-ray photoemission spectroscopy, we show how to systematically minimize both Eu silicide and Si oxide formation to the sub-monolayer regime-and how to ultimately interface-engineer chemically clean, heteroepitaxial and ferromagnetic EuO/Si (001) in order to create a strong spin filter contact to silicon.
authors.affiliation: Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425 Jülich, Germany.|JARA Jülich-Aachen Research Alliance, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Caspers
authors.affiliation: DESY Photon Science, Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gloskovskii
authors.affiliation: Helmholtz-Zentrum für Materialien und Energie, BESSY II, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Gorgoi
authors.affiliation: Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Besson
authors.affiliation: Peter Grünberg Institut (PGI-5) und Ernst Ruska-Centrum für Mikroskopie und Spektroskopie mit Elektronen, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Luysberg
authors.affiliation: Peter Grünberg Institut (PGI-1), Forschungszentrum Jülich, 52425 Jülich, Germany.|JARA Jülich-Aachen Research Alliance, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: K Z
authors.initials: KZ
authors.lastname: Rushchanskii
authors.affiliation: Peter Grünberg Institut (PGI-1), Forschungszentrum Jülich, 52425 Jülich, Germany.|JARA Jülich-Aachen Research Alliance, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ležaić
authors.affiliation: Department of Physics, University of California, Davis, California, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Fadley
authors.affiliation: DESY Photon Science, Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Drube
authors.affiliation: Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, 52425 Jülich, Germany.|JARA Jülich-Aachen Research Alliance, Forschungszentrum Jülich, 52425 Jülich, Germany.|Fakultät für Physik und Center for Nanointegration CENIDE, Universität Duisburg-Essen, 47048 Duisburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Müller