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MA: Fachverband Magnetismus

MA 29: Micro- and Nanostructured Magnetic Materials

MA 29.1: Vortrag

Mittwoch, 13. März 2013, 15:00–15:15, H23

On the correlation between material morphology, cation distribution and magnetic properties in nanocrystalline ZnFe₂O₄ — •Christian Reitz, Christian Suchomski, and Torsten Brezesinski — Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen

Magnetic materials exhibiting both a high saturation magnetization and low coercivity are of interest to researchers from a wide range of disciplines, including information technology, biomedicine and so forth. Inverse spinel ferrites, in which the Fe³⁺ ions are distributed equally among the octahedral and tetrahedral binding sites, constitute a promising class of materials for such applications. Bulk zinc ferrite (ZFO), by contrast, is known to adopt a normal spinel structure, which leads to antiferromagnetic behavior. Nonetheless, in recent years it has been shown that the cation distribution and, thus, also the magnetic properties of ZFO and related spinel ferrites can be effectively tailored by changing the material morphology and by reducing the grain size to the nanometer level. Here we report facile synthetic routes for the preparation of sub 10 nm diameter nanoparticles and ordered mesoporous thin films of partially inverted ZFO. These oxide materials exhibit magnetic characteristics that strongly depend on the morphology, grain size and the cation distribution. The latter was determined by both XPS and Mössbauer spectroscopy.