Effect of albumin coating on the magnetic behavior of Mn ferrite nanoclusters.

The effect of clustering induced by albumin coating on the magnetic behaviour of ultra-small MnFeO nanoparticles has been systematically investigated and compared with that in pure Mn ferrite nanoparticle dense assembly, using a mesoscopic scale approach and numerical simulations reproducing the experimental findings well. Our results provide evidence that in the coated system, the interplay between intra-particle and intra-cluster exchange interactions strongly affects the exchange bias and coercive field values, with the dipolar interactions playing a minor role. Instead, the albumin coating does not affect the thermal stability of the observed superspin glass phase, the freezing temperature being similar in the coated and uncoated systems.