Regensburg 2010 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 29: Nanostructured Materials II
MM 29.4: Vortrag
Mittwoch, 24. März 2010, 12:45–13:00, H16
Electrochemical tuning of the electrical resistance of nanoporous gold prepared by dealloying — Patrick Wahl1, •Thomas Traußnig1, Hai-Jun Jin2, Stephan Landgraf3, Jörg Weissmüller2, and Roland Würschum1 — 1Inst. f. Materialphysik, TU Graz, Graz, Austria — 2Inst. f. Nanotechnologie, Karlsruher Institut für Technologie, Karlsruhe, Germany — 3Inst. f. Physikal. u. Theoret. Chemie, TU Graz, Graz, Austria
Electric field-induced tuning of material properties is usually restricted to nonmetals such as semiconductors and piezoelectric ceramics. Studies on the property tuning (e.g., resistance tuning [1,2]) of metals have been initiated making use of nanocomposites of porous nanophase metals and liquid electrolytes. Triggered by recent findings that the surface stress-charge response of nanoporous gold sensitively depends on adsorbed oxygen [3], the variation of the electrical resistance of nanoporous gold upon electrochemical charging in an aqueous electrolyte is studied. Nanoporous gold is prepared by dealloying. Reversible variations of the resistance up to ca. 50% occur due to the formation of an electro-chemical double layer and the chemical interaction of the electrolyte with the surface (primarily the reversible adsorption of OH/O and desorption of O). The charge-induced variation of the resistance in the various electrochemical regimes is discussed.
[1] M. Sagmeister et al., Phys. Rev. Lett. 96 (2006) 156601; [2] A.K. Mishra et al., J. Appl. Phys. 103 (2008) 094308; [3] Hai-Jun Jin et al., Surface Science 602 (2008) 3588. Financial support by the FWF Austrian Science Fund is appreciated (project S10405-N16).