Berlin 2005 – scientific programme
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O: Oberflächenphysik
O 48: Oxide und Isolatoren II
O 48.2: Talk
Tuesday, March 8, 2005, 16:00–16:15, TU EB107
Growth of vanadium oxides on Cu3Au(111) — •Michael Hafemeister, Jürgen Middeke, Ralf-Peter Blum, and Horst Niehus — Humboldt-Universität zu Berlin, Institut für Physik/ASP, Newtonstraße 15, D-12489 Berlin
Systematic studies of the deposition of transition metals on different oxidic substrates illustrate the trend of increased wetting and enhanced growth depending on the oxygen affinity of the deposit. According to the concept of an oxygen-containing substrate we found that different transition metal oxide films (VOx, NbOx, MoOx) of high quality can be obtained on Cu3Au(100). In order to analyze the influence of structural factors of the substrate, the growth of VOx on Cu3Au(111) has been investigated. STM studies show the 2D growth of a single-phase VOx film with a honeycomb structure (2.7nm), that can be recognized as a Moiré pattern created by a hexagonal superlattice with a lattice parameter of 0.3nm. This structure could be confirmed by LEED images. The evaluation of AES data suggests a VO stoichiometry. From low energy ion scattering we conclude that the top layer is composed of oxygen. Finally the formation of a VO(111) layer is proposed, exposing a lattice of 0.3nm which is just slightly lager than 0.28nm known from the bulk vanadium monoxide.