Negative Magnetoresistance Phenomenon in Diluted Granular Multilayers Co80Fe20(t)|Al2O3

Several complex theories explaining the phenomenon of negative magnetoresistance (NMR) are discussed, observed in insulating diluted granular multilayers Co80Fe20(t)|Al2O3. In fact, this investigation is re-analyzing the experimental measurements of Co80Fe20 with low nominal thickness t = 0.7 nm of granular layers obtained earlier. Two theories such as quantum interference model and localized magnetic moments model are confronted with experimental measurements in order to provide physical explanations to NMR phenomenon.