Berlin 2012 – wissenschaftliches Programm
MM 17.30: Poster
Montag, 26. März 2012, 17:00–19:00, Poster B
Electrochemical tuning of the electrical resistance of nanoporous platinum produced by dealloying — •Eva-Maria Steyskal1, Maximilian Besenhard1, Thomas Traußnig1, Jörg Weissmüller2, Stephan Landgraf3, and Roland Würschum1 — 1Inst. f. Materialphysik, TU Graz, Graz, Austria — 2Inst. f. Werkstoffphysik u. Werkstofftechnologie, TU Hamburg-Harburg, Hamburg, Germany — 3Inst. f. Physikalische u. Theoretische Chemie, TU Graz, Graz, Austria
Nanostructured materials can exhibit electrochemically tunable properties due to their high surface-to-volume ratio. Based on this concept, reversible tunig of mechanical, electrical, and magnetic properties has been demonstrated recently. The present work studies the tunability of the electrical resistance of nanoporous platinum, produced by dealloying of a Cu75Pt25 alloy. In the investigated potential range, the charge coefficient (Δ R / R0) / Δ Q exhibits a sign inversion, thus differing from previous results on nanocrystalline, compacted platinum powder  as well as nanoporous gold . The resistance behavior in the two charge-coefficient-regimes is attributed to variations in the charge carrier density and interfacial scattering in the positive, as well as the oxygen coverage in the negative sign region. Financial support by the FWF Austrian Science Fund is appreciated (project S10405-N16).
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