Size analysis of single-core magnetic nanoparticles
Artikel i vetenskaplig tidskrift, 2017

Single-core iron-oxide nanoparticles with nominal core diameters of 14 nm and 19 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.

Size distribution

Dynamic light scattering

Transmission electron microscopy

Single-core nanoparticles

Magnetization

Brownian and Néel relaxation

Författare

Frank Ludwig

Technische Universität Braunschweig

Christoph Balceris

Technische Universität Braunschweig

Thilo Viereck

Technische Universität Braunschweig

Oliver Posth

Physikalisch-Technische Bundesanstalt (PTB)

Uwe Steinhoff

Physikalisch-Technische Bundesanstalt (PTB)

Helena Gavilan

CSIC - Instituto de Ciencia de Materiales de Madrid (ICMM)

Rocio Costo

CSIC - Instituto de Ciencia de Materiales de Madrid (ICMM)

Lunjie Zeng

Chalmers, Fysik, Eva Olsson Group

Eva Olsson

Chalmers, Fysik, Eva Olsson Group

Christian Jonasson

Christer Johansson

Journal of Magnetism and Magnetic Materials

0304-8853 (ISSN)

Vol. 427 19-24

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1016/j.jmmm.2016.11.113