Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 24: Oberfl
ächenmagnetismus
MA 24.4: Vortrag
Dienstag, 8. März 2005, 11:15–11:30, TU A060
Tunable Magnetic Properties of Nanocrystalline Pd-Ni Alloy — •Sadhan Ghosh1, Christian Lemier1, Jörg Weissmüller1,2, and Viswanath Raghavan Nadar1 — 1Forschungszentrum Karlsruhe, Institut für Nanotechnologie, Karlsruhe — 2Fachrichtung Technische Physik, Universität des Saarlandes, 66041 Saarbrücken
Ferromagnetism is strongly related to the electronic structure density, therefore it is interesting to study how far one can modify the magnetic order of solids by changing their electron density. While this is usually done by alloying, one can also change the charge density reversibly by inducing space−charge regions at surfaces. This is particularly interesting in nanostructured materials, since the high surface to volume ratio maximizes the effect of the local property changes on the macroscopic materials behaviour [1]. It has been demonstrated that the polarized nanoporous metals exhibit large volumetric expansion and contraction in phase with the applied electrode potential [2]. In the present work, we report the variation of the magnetic moment of charged nanocrystalline Pd−Ni alloy, produced by the inert−gas condensation method, by in−situ magnetization experiments. We discuss the relative variation of charge−induced magnetization by changing the alloy composition as well as changing the electrochemical environment. [1] Gleiter H., Weissmüller J., Wollersheim O., Würschum R. Acta mater. 49 (2001), 737; [2] Weissmüller, J., Viswanath, R.N., Kramer, D., Zimmer, P., Würschum, R., Gleiter, H. Science 300 (2003), 312.