Publications

Magnetic response of dilute cobalt nanoparticles in an organic matrix : the effects of aging and interface chemistry

Wilcoxon, Jess P.; Wilcoxon, Jess P.; Venturini, Eugene L.; Provencio, P.N.

We report studies of the magnetic response of dilute frozen solutions of nanocrystalline Co particles grown in inverse micelles. Crystalline nanoclusters which initially exhibit only a small fraction of the bulk saturation moment restructure in solution without any change in cluster size or blocking temperature over a period of {approx}30-60 days, finally yielding a moment/atom which exceeds that of bulk Co. The saturation magnetism maintains its enhanced value for temperatures up to the melting point of the solvent matrix, but is strongly dependent on surface active additives and molecular oxygen.