title: Galvanic Exchange in Colloidal Metal/Metal-Oxide Core/Shell Nanocrystals.
abstract: While galvanic exchange is commonly applied to metallic nanoparticles, recently its applicability was expanded to metal-oxides. Here the galvanic exchange is studied in metal/metal-oxide core/shell nanocrystals. In particular Sn/SnO2is treated by Ag+, Pt2+, Pt4+, and Pd2+. The conversion dynamics is monitored by in situ synchrotron X-ray diffraction. The Ag+treatment converts the Sn cores to the intermetallic AgxSn (x∼ 4) phase, by changing the core's crystal structure. For the analogous treatment by Pt2+, Pt4+, and Pd2+, such a galvanic exchange is not observed. This different behavior is caused by the semipermeability of the naturally formed SnO2shell, which allows diffusion of Ag+but protects the nanocrystal cores from oxidation by Pt and Pd ions.
authors.affiliation: Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Altenberger Straße 69, A-4040 Linz, Austria; Department of Condensed Matter Physics, Charles University Prague, Ke Karlovu 5, 121 16 Praha 2, Czech Republic.
authors.forename: Dominik
authors.initials: D
authors.lastname: Kriegner
authors.affiliation: Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Altenberger Straße 69, A-4040 Linz, Austria; Materials Science Department (Materials for Electronics and Energy Technology), Friedrich-Alexander Universität, Fürtherstrasse 250, D-90429 Nürnberg, Germany.
authors.forename: Mykhailo
authors.initials: M
authors.lastname: Sytnyk
authors.affiliation: Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, Center for Surface and Nanoanalytics (ZONA), Johannes Kepler University, Altenberger Straße 69, A-4040 Linz, Austria; Laboratory for Electron Microscopy, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Groiss
authors.affiliation: Institute of Semiconductor and Solid State Physics, Johannes Kepler University , Altenberger Straße 69, A-4040 Linz, Austria.
authors.forename: Maksym
authors.initials: M
authors.lastname: Yarema
authors.affiliation: Institute of Semiconductor and Solid State Physics, Johannes Kepler University , Altenberger Straße 69, A-4040 Linz, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Grafeneder
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.affiliation: Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany.
authors.forename: Ann-Christin
authors.initials: AC
authors.lastname: Dippel
authors.affiliation: Laboratory for Electron Microscopy, Karlsruhe Institute of Technology , D-76131 Karlsruhe, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Meffert
authors.affiliation: Laboratory for Electron Microscopy, Karlsruhe Institute of Technology , D-76131 Karlsruhe, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Gerthsen
authors.affiliation: Institute of Semiconductor and Solid State Physics, Johannes Kepler University , Altenberger Straße 69, A-4040 Linz, Austria.
authors.forename: Julian
authors.initials: J
authors.lastname: Stangl
authors.affiliation: Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Altenberger Straße 69, A-4040 Linz, Austria; Materials Science Department (Materials for Electronics and Energy Technology), Friedrich-Alexander Universität, Fürtherstrasse 250, D-90429 Nürnberg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Heiss