Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 51: Magnetism Poster B

MA 51.24: Poster

Donnerstag, 4. April 2019, 15:00–18:00, Poster C

Spin structure of superparamagnetic iron oxide nanoparticles — •Tobias Köhler¹, Artem Feoktystov¹, Oleg Petracic², Emmanuel Kentzinger², Tanvi Bhatnagar^{2, 4}, Sascha Ehlert³, Ulrich Rücker², Rafal Dunin-Borkowski⁴, Andras Kovacs⁴, and Thomas Brückel² — ¹Forschungszentrum Jülich GmbH, JCNS at MLZ, 85748 Garching, Germany — ²Forschungszentrum Jülich GmbH, JCNS-2 and PGI-4, JARA-FIT, 52425 Jülich, Germany — ³Forschungszentrum Jülich GmbH, JCNS-1, 52425 Jülich, Germany — ⁴Forschungszentrum Jülich GmbH, Ernst Ruska-Centrum für Mikroskopie und Spektroskopie mit Elektronen, 52425 Jülich, Germany

We have studied superparamagnetic iron oxide nanoparticles by various experimental techniques in order to characterize the observed reduced saturation magnetization as compared to bulk. Particles of the size of 12 and 15 nm have been studied via small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), inductively coupled plasma with optical emission spectroscopy (ICP-OES) and magnetometry to obtain a detailed understanding of the internal magnetization distribution. Small amounts of spherical particles were dispersed in paraffin, so that inter-particle interactions can be neglected. The shapes of the magnetometry curves confirm a superparamagnetic behavior. The presence of exchange bias indicates an antiferromagnetic, wüstite contribution to the particle composition. Small-angle scattering of polarized neutrons (SANSPOL) will provide insights into the inner spin structure.