Dresden 2003 – wissenschaftliches Programm
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M: Metallphysik
M 27: Nanoskalige Materialien II
M 27.5: Vortrag
Dienstag, 25. März 2003, 17:30–17:45, IFW D
Charge Influenced Reversible Strain in Nanocrystalline Porous Gold — •Dominik Kramer1, Raghavan Nadar Viswanath1, Jörg Weissmüller1,2 und Herbert Gleiter1 — 1Forschungszentrum Karlsruhe, Institut für Nanotechnologie, Karlsruhe, Germany — 2Universität des Saarlandes, Fachrichtung Technische Physik, Saarbrücken, Germany
It has been suggested that it should be possible to tune electron-density dependent structural and physical properties of systems with a high surface-to-volume-ratio, especially nanocrystalline materials, by changing the charge density at the surface [1]. One example of such a property is the lattice constant and the dimension of nanocrystalline porous metal samples. Here we show that the strain in a metal can be reversibly changed by charging the nanoporous sample in an electrolyte impregnating the pores. We present in-situ dilatometer and X-ray measurements of nanoporous gold that was prepared by dealloying a gold-silver alloy in perchloric acid. Reversible changes of the length of the samples were observed in various electrolytes, dependent on the potential vs. a reference electrode. It is suggested to exploit this effect to construct nanoporous metallic actuators. They need larger currents than piezoelectric materials, but have the advantage to work with small voltages.
[1]. H. Gleiter, J. Weissmüller, O. Wollersheim and R. Würschum, Nanocrystalline Materials: a way to solids with tunable electronic structure and properties? Acta Mater. 49, 737 (2000).