Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5491149 | Journal of Magnetism and Magnetic Materials | 2017 | 9 Pages |
Abstract
Single-core iron-oxide nanoparticles with nominal core diameters of 14Â nm and 19Â nm were analyzed with a variety of non-magnetic and magnetic analysis techniques, including transmission electron microscopy (TEM), dynamic light scattering (DLS), static magnetization vs. magnetic field (M-H) measurements, ac susceptibility (ACS) and magnetorelaxometry (MRX). From the experimental data, distributions of core and hydrodynamic sizes are derived. Except for TEM where a number-weighted distribution is directly obtained, models have to be applied in order to determine size distributions from the measurand. It was found that the mean core diameters determined from TEM, M-H, ACS and MRX measurements agree well although they are based on different models (Langevin function, Brownian and Néel relaxation times). Especially for the sample with large cores, particle interaction effects come into play, causing agglomerates which were detected in DLS, ACS and MRX measurements. We observed that the number and size of agglomerates can be minimized by sufficiently strong diluting the suspension.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Frank Ludwig, Christoph Balceris, Thilo Viereck, Oliver Posth, Uwe Steinhoff, Helena Gavilan, Rocio Costo, Lunjie Zeng, Eva Olsson, Christian Jonasson, Christer Johansson,