Interaction effects in magnetic granular systems

Interactions in magnetic granular systems are difficult to address in real systems. Several experimental results have been obtained along the last 50 years, but few theoretical approaches have been developed to account for these extremely complex systems. A brief review on the role of interactions on the magnetic properties of granular magnetic systems is given, with a focus on a novel approach known as interacting superparamagnetic model. Two different systems are tested, and the results are discussed in terms of such phenomenological model.