Abstract

The magnetic and transport properties of ferromagnetic clusters embedded in a metallic host are studied. A simple model is presented to explain the observed behaviour of the magnetoresistance in such systems. The role played by both the dipolar interaction between the clusters and the ratio of the electronic mean free path in the non-magnetic material to the average inter-cluster distance is clarified. Finally, a suggestion is made of systems in which the best magnetoresistance ratios are expected to be found.