| Abstract: | Nanometer ferromagnetic metal-semiconductor matrix Fe-In2O3 granular films are fabricated by the radio frequency sputtering. Magnetic properties and the giant magnetoresistance (GMR) effect of Fex(In2O3)1x granular film samples are studied. The result shows that the magne-toresistance (MR) ratio/0 value of the granular film samples with Fe volume fraction x = 35% is 4.5% at room temperature. The temperature dependence (T = 1.5-300 K) of the MR ratio /0 value of Fe0.35(In2O3)0.65 granular films shows that /0 value below 10 K increases rapidly with the decrease of the temperature, and when T = 2 K,/0 value is 85%. Through the study of the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it has been found that, when the temperature decreases to a critical point TP = 10 K, the change of the structure in Fe0.35(In2O3)0.65 granular films results in the transformation of state from ferromagnetic to spin-glass-like. The remarkable increase of the MR ratio ???/??0 value of Fe0.35(In2O3)0.65 granular films below 10 K seems to arise from the peculiar conducting mechanism of the granular film samples in the spin-glass-like state. |
