Field-responsive colloidal assemblies defined by magnetic anisotropy

Autor(en)

Gabi Steinbach, Michael Schreiber, Dennis Nissen, Manfred Albrecht, Ekaterina Novak, Pedro A. Sanchez, Sofia S. Kantorovich, Sibylle Gemming, Artur Erbe

Abstrakt

Particle dispersions provide a promising tool for the engineering of functional materials that exploit self-assembly of complex structures. Dispersion made from magnetic colloidal particles is a great choice; they are biocompatible and remotely controllable among many other advantages. However, their dominating dipolar interaction typically limits structural complexity to linear arrangements. This paper shows how a magnetostatic equilibrium state with noncollinear arrangement of the magnetic moments, as reported for ferromagnetic Janus particles, enables the controlled self-organization of diverse structures in two dimensions via constant and low-frequency external magnetic fields. Branched clusters of staggered chains, compact clusters, linear chains, and dispersed single particles can be formed and interconverted reversibly in a controlled way. The structural diversity is a consequence of both the inhomogeneity and the spatial extension of the magnetization distribution inside the particles. We draw this conclusion from calculations based on a model of spheres with multiple shifted dipoles. The results demonstrate that fundamentally new possibilities for responsive magnetic materials can arise from interactions between particles with a spatially extended, anisotropic magnetization distribution.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Helmholtz-Zentrum Dresden-Rossendorf, Universität Augsburg, Ural Federal University, Technische Universität Chemnitz

Journal

Physical Review E

Band

100

Anzahl der Seiten

10

ISSN

2470-0045

DOI

https://doi.org/10.1103/PhysRevE.100.012608

Publikationsdatum

07-2019

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie

Schlagwörter

ASJC Scopus Sachgebiete

Condensed Matter Physics, Statistical and Nonlinear Physics, Statistics and Probability

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/0bb1e8b5-b14b-4509-9aad-69ad251bdb67