Self-assembly and flux closure studies of magnetic nanoparticle rings

Alexander Wei, Birck Nanotechnology Center, Purdue University
Takeshi Kasama, Technical University of Denmark
Rafal E. Dunin-Borkowski, Technical University of Denmark

Date of this Version



J. Mater. Chem., 2011,21, 16686-16693 DOI: 10.1039/C1JM11916H


Thermoremanent magnetic nanoparticles (MNPs) can self-assemble into rings through dipolar interactions, when dispersed under appropriate conditions. Analysis of individual MNP rings and clusters by off-axis electron holography reveals bistable flux closure (FC) states at ambient temperatures, and their reversible switching by magnetic field gradients. We introduce a line-bond formalism to describe the coupling between MNPs.


Nanoscience and Nanotechnology