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MA: Fachverband Magnetismus
MA 46: Magnetic particles and clusters
MA 46.5: Vortrag
Donnerstag, 4. April 2019, 12:30–12:45, H52
Accessing ferrofluid in-field dynamics via Mössbauer spectroscopy — •Joachim Landers1, Soma Salamon1, Hilke Remmer2, Frank Ludwig2, and Heiko Wende1 — 1Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen — 2Institute for Electrical Measurement Science and Fundamental Electrical Engineering, TU Braunschweig
Ferrofluids of coated iron-oxide nanoparticles were studied in the presence of external magnetic fields using Mössbauer spectroscopy, utilizing its ability to simultaneously gain insight into different magnetic phenomena. For nanoparticles ranging from 5 to 25 nm in core diameter, dynamic relaxation processes, namely Néel relaxation and Brownian particle motion, were analyzed by this method, with results being verified by AC-susceptometry and in agreement with the fluids' macroscopic viscosity. From the same set of Mössbauer spectra, additional information could be extracted regarding the particles' magnetic alignment relative to the field direction, as well as the degree of surface spin canting and the presence of particle agglomerates. Funding by the DFG within SPP 1681 is gratefully acknowledged.