Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 31: Magnetic Particles and Clusters I
MA 31.7: Vortrag
Donnerstag, 26. März 2009, 11:45–12:00, HSZ 401
Spectroscopic investigation of magnetic CoPt nanoparticles — •Leif Glaser1, Michael Martins1, Christine Boeglin3, Vesna Alesandrovic2, Host Weller2, and Wilfried Wurth1 — 1Department Physik, Universität Hamburg, 22761 Hamburg , Germany — 2Department Chemie, Universität Hamburg, 20146 Hamburg, Germany — 3Institut de Physique et Chimie des Materiaux de Strasbourg,23, 67034 Strasbourg, France
The size dependent magnetic properties of wetchemically synthesized CoxPt100−x nanoparticles (3.7nm to 8.4nm) in their organic ligand shell were investigated at the Cobalt L-edges with X-ray magnetic circular dichroism (XMCD). A 7 Tesla high field magnet setup was used at the Bessy II storage ring. Oxidization effects due to the synthesis process and post synthesis aging were adressed by choosing particles of equal size, but different age and storage condition. The particles were deposited on silicon wafers as a single layered thin film using dip and spin coating techniques. The quality of the films was checked with Scanning Electron Microscopy (SEM).
Strongly enhanced magnetic moments of the investigated particles compared with bulk and thin film systems could be determined, The orbital magnetic moments of fresh particles displayed a favour of in plane magnetization increasing with cluster size.
Size dependent oxidization and size dependent aging effects could be detected and explained by model calculations.
Funding for this project by BMBF under contract 05 KS4 GUB/6 is gratefully acknowledged.