Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65
MA 20.101: Poster
Montag, 7. März 2005, 14:00–18:00, Poster TU C
Variation of the Magnetic Moment of Nickel by Electrochemical Charging — •Christian Lemier1, Sadhan Ghosh1, Jörg Weissmüller1,2, and Raghavan N. Viswanath1 — 1Institut für Nanotechnologie, Forschungszentrum Karlsruhe GmbH — 2Fachrichtung Tech. Physik, Universität des Saarlandes
It has been proposed that changes in the electronic structure in superficial space-charge regions may substantially affect the properties of metals near the surface [1]. In nanostructured materials, due to the high surface to volume ratio, even changes in a thin surface layer involve considerable amounts of the volume fraction. Therefore, these materials can be used to study the effect of charging on the surface properties. An implementation of this principle is to use a nanoporous material immersed in an electrolyte. Application of an electric field gives rise to an electric double layer region at the metal-electrolyte interface and allows to store a considerable amount of charge. Recently, changes in the lattice parameter of nanoporous Pt [2] and macroscopically bending of nanoporous Au cantilevers [3] have been observed. Here, we examine the possibility of tuning of the magnetic moment of Ni, deposited with a few monolayer thickness on nanoporous Au, and on high surface area Carbon. Changes in the magnetic moment of up to 10% have been observed by in-situ charging experiments. Special focus has been on the discrimination of the relative influence of band-filling versus that of hydride formation, OH adsorption and oxidation. [1] H. Gleiter, et al., Acta Mater. 49 (2001), 737. [2] J. Weissmüller,et al., Science 300 (2003), 312. [3] D. Kramer, et al., Nano Lett. 4 (2004), 793.