Extra-Large Magnetoresistance in Fe/In2O3 Granular Films

Nanogranular Fe0.35/(In2O3)0.65 films with complex magnetic structure were prepared by the rf sputtering method. An extra-large magnetoresistance up to 506% was obtained at 2.2 K, which is two orders of magnitude larger than that obtained at room temperature. This is related to the interaction with the impurities influencing the local magnetization, which is quite different from the spin-dependent tunnelling effect at room temperature. The interspacing Fe atoms dispersed in the In2O3 matrix play an important role in the transportation properties of carriers at low temperature.