Regensburg 2010 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 9: Magnetic Particles, Clusters
MA 9.5: Vortrag
Montag, 22. März 2010, 16:15–16:30, H23
Structural and Magnetic Deconvolution of FePt/FeOx-Nanoparticles using X-Ray Magnetic Circular Dichroism — •Daniela Nolle1, Eberhard Goering1, Giesela Schütz1, Albert Figuerola2, and Liberato Manna2 — 1MPI for Metals Research, Heisenbergstrasse 3, 70569 Stuttgart, Germany — 2IIT, Via Morego, 30 16163 Genova, Italy
In order to analyse the related magnetic and structural properties of bi-component nanoparticular systems we present XAS and XMCD studies at the Fe L2,3-edges simultaneously performed in surface sensitive total electron yield (TEY) and bulk sensitive transmission mode, at room and low temperatures. This provides the separation of volume and surface related properties especially. The investigated systems were made up of FePt/FeOx hybrid nanoparticles of different diameters. A detailed deconvolution in terms of a linear superposition of suitable reference spectra (FePt, γ-Fe2O3, and Fe3O4) is presented. Absolute magnetic moments, determined by XMCD sum rule analysis, provide reliable and consistent magnetization values, in contrary to SQUID related results, due to the unknown size of the organic ligand shell around each nanoparticle. For the necessary magnetic characterization of these nanoparticles, SQUID results must be renormalized by the complementary XAS/XMCD investigations. Finally this method demonstrates the strength of simultaneously performed XMCD experiments using different scanning depth measurement modes for the investigation and characterization of nanoparticular systems, which are consistent and supplemental to corresponding SQUID measurements.