Self-assembly of magnetic Ni nanoparticles into 1D arrays with antiferromagnetic order

Christian Binek, University of Nebraska at Lincoln
Sarbeswar Sahoo, University of Nebraska-Lincoln
Srinivas Polisetty, University of Nebraska-Lincoln
Xi He, University of Nebraska at Lincoln

Document Type Article

Published in Nanotechnology 20.

Abstract

In this paper, we report on the magnetic properties of isolated nanoparticles and interacting nanochains formed by the self-assembly of Ni nanoparticles. The magnetic properties were studied using superconducting quantum interference device (SQUID) magnetometry and magnetic force microscopy (MFM). We demonstrate that single-domain Ni nanoparticles spontaneously form one-dimensional (1D) chains under the influence of an external magnetic field. Furthermore, such magnetic field-driven self-assembly in conjunction with surface templating produces regular arrays of 1D nanochains with antiferromagnetic intra-chain order. The antiferromagnetic order, which is in striking contrast to what is found for non-interacting nanoparticle assemblies within the chains, can be evidenced from MFM and SQUID measurements.