Regensburg 2007 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 31: Nano structured materials III
MM 31.2: Vortrag
Donnerstag, 29. März 2007, 12:00–12:15, H4
Tuneable electrical resistance of nanocrystalline platinum — •Martin Sagmeister1, Ulrich Brossmann1, Stefan Landgraf2, and Roland Würschum1 — 1Institut für Materialphysik, TU Graz, Petersgasse 16, 8010 Graz, Austria — 2Institut für Physikalische und Theoretische Chemie, TU Graz, Technikerstrasse 4, 8010 Graz, Austria
Electric field-induced tuning of material properties is usually restricted to nonmetals such as semiconductors and piezoelectric ceramics. Based on nanocrystalline materials, metals with tunable mechanical [1], magnetic [2], and electronic properties [3] could recently be generated. We show that variations of the electrical resistance of a metal (platinum) in the range of several percent can be reversibly induced at low charging voltages making use of a nanocrystallite-electrolyte composite [3]. Surface charging of the porous nanocrystallite network occurs by the formation of an electro-chemical double layer. The charge-induced resistance variation is analyzed taking into account the modification of the charge carrier density and scattering rate by surface charging. The contribution rising from the charge-induced variation of the lattice constant is found to be small.
[1] J. Weissmüller, R.N. Viswanath, D. Kramer, P. Zimmer, R. Würschum, and H. Gleiter, Science 300 (2003) 312
[2] H. Drings, R.N. Viswanath, D. Kramer, Chr. Lemier, J. Weissmüller, and R. Würschum, Appl. Phys. Lett. 88 (2006) 253103
[3] M. Sagmeister, U. Brossmann, S. Landgraf, and R. Würschum: Phys. Rev. Lett. 96 (2006) 156601