Dresden 2017 – wissenschaftliches Programm
MA 41.9: Vortrag
Mittwoch, 22. März 2017, 17:15–17:30, HSZ 101
Magnetic characterization of cobalt ferrite nanoparticles in PEG-solution studied by Mössbauer spectroscopy and magnetic AC-susceptometry — •Samira Webers1, Joachim Landers1, Soma Salamon1, Melissa Hermes2, Annette M. Schmidt2, and Heiko Wende1 — 1Faculty of Physics, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen — 2Institute for Physical Chemistry, University of Cologne
Spherical, monodisperse cobalt ferrite nanoparticles dispersed in an aqueous solution display fast Brownian motion. By adding polyethylene glycol (PEG) the viscosity of the mixture increases and the particle motion is slowed by the PEG chains. We investigate the influence of different PEG chain lengths and various concentrations resulting in similar macroscopic properties by magnetic characterization of the particle motion via Mössbauer spectroscopy and AC-susceptometry (ACS). The main aspect is to study the particle-matrix interaction in macroscopic similar mixtures which differ in their microscopic composition. Since the particles are in the size of the structural units of the matrix, the relative length scale of the magnetic particles compared to the size of the structural units of the polymer gets relevant and is expected to influence the particle mobility. Further structural characterization of the particles regarding to the particle size and spinel structure are performed by low temperature in-field Mössbauer spectroscopy. To crosscheck the Mössbauer results, the Brownian rotation frequency of the particles is studied by ACS. This work is supported by the DFG-Priority Programme SPP1681.