Magnetic behaviour of negatively charged nickel(II) hexacyanoferrate(III) coordination nanoparticles

Negatively charged 4 nm bimetallic Ni(II)-Fe(III) cyanide-bridged nanoparticles were obtained and isolated by different coating agents. The magnetic properties of the particles were studied in the powder form and in diluted samples. A spin-glass like behaviour occurs in the concentrated sample, while the magnetic behaviour of the diluted ones strongly depends on the method used to isolate the nanoparticles. Only high dilution in a polymer matrix leads to a single-domain superparamagnetic behaviour, with a blocking temperature of 3.5 K. (C) 2008 Elsevier B.V. All rights reserved.