1 Department of Physics, Technical University of Denmark2 Center for Nanoteknologi, Center, Technical University of Denmark3 Department of Energy Conversion and Storage, Technical University of Denmark
We demonstrate that exchange interactions between antiferromagnetic nanoparticles of 57Fe-doped NiO can be varied by simple macroscopic treatments. Mössbauer spectroscopy studies of the superparamagnetic relaxation behaviour show that grinding or suspension in water of nanoparticles of NiO can significantly reduce interparticle interactions. Slow drying of aqueous suspensions of NiO nanoparticles did not lead to enhanced interparticle interactions. This is opposite to the behaviour of α-Fe2O3 (hematite) nanoparticles.
Nanotechnology, 2006, Vol 17, Issue 12, p. 2835-2839