Dresden 2003 – scientific programme
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M: Metallphysik
M 27: Nanoskalige Materialien II
M 27.4: Talk
Tuesday, March 25, 2003, 17:15–17:30, IFW D
Charge influenced reversible strain in nanocrystalline porous Pt — •VISWANATH RAGHAVAN NADAR1, JÖRG WEISSMÜLLER1,2, DOMINIK KRAMER1, ROLAND WÜRSCHUM3, and HERBERT GLEITER1 — 1Institut für Nanotechnologie, Forschungszentrum Karlsruhe, Karlsruhe, Germany — 2Universität des Saarlandes, Fachrichtung Technische Physik, Saarbrücken, Germany — 3Technische Universität Graz, Institut für Technische Physik, Graz, Austria
We present the results of our recent findings that the lattice constant and the dimension of a metal can be changed reversibly by the strain induced by varying the electric charge density of the surface. The results presented here represent an experimental evidence in support of the suggestion that a wider range of properties of metals may be reversibly tuned by simply adding or withdrawing charges at surfaces or internal interfaces by means of an applied electric potential. A reversible strain amplitude in excess of 0.1% has been obtained by charging inter-connected nm sized three dimensional porous structured nanocrystalline platinum immersed in aqueous and non-aqueous electrolytes at different external applied potentials. The experimental techniques, in-situ dilatometry and in-situ X-ray diffraction, have been used to estimate the crystal strain. The variation of the strain obtained from the platinum metal is remarkable since analogous findings have previously only been observed for ionic and covalently bonded materials such as carbon nanotubes or conducting polymers.