title: Synthesis of Au microwires by selective oxidation of Au-W thin-film composition spreads.
abstract: We report on the stress-induced growth of Au microwires out of a surrounding Au-W matrix by selective oxidation, in view of a possible application as 'micro-Velcro'. The Au wires are extruded due to the high compressive stress in the tungsten oxide formed by oxidation of elemental W. The samples were fabricated as a thin-film materials library using combinatorial sputter deposition followed by thermal oxidation. Sizes and shapes of the Au microwires were investigated as a function of the W to Au ratio. The coherence length and stress state of the Au microwires were related to their shape and plastic deformation. Depending on the composition of the Au-W precursor, the oxidized samples showed regions with differently shaped Au microwires. The Au48W52composition yielded wires with the maximum length to diameter ratio due to the high compressive stress in the tungsten oxide matrix. The values of wire length (35μm) and diameter (2μm) achieved at the Au48W52composition are suitable for micro-Velcro applications.
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Hamann
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Hayo
authors.initials: H
authors.lastname: Brunken
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Salomon
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Meyer
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Alan
authors.initials: A
authors.lastname: Savan
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany; Materials Research Department, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Ludwig
keywords: 10.07; 20.11; Thin films; WO3; combinatorial materials science; microwires; velcro