Speaker
Description
The properties of antiferromagnetic materials at the nanoscale are important for future spintronic devices. We study the magnetic properties of goethite at the nanoscale by combining X-ray linear dichroism (XLD) spectroscopy and X-ray photoemission electron microscopy. Complementary scanning electron microscopy is used to correlate the magnetic properties of individual goethite nanoparticles with their actual morphology. Temperature and orientation dependent XLD spectra of individual goethite nanoparticles, suggest a magnetic ordering transition close to 400 K corresponding to the Néel temperature of bulk goethite. Predominantly isotropic XLD spectra reveal isotropic magnetic properties of individual nanoaprticles despite of their acicular shape. We attribute this finding to the presence of multiple antiferromagnetic domains within the particles due their polycrystalline microstructure.
