Giant Hall Effect of Fe_45.51(Al₂O₃ )_54.49 Nano-granular Film

A series of Fe_45.51(Al₂O₃ )_54.49 nano-granular films were prepared using ion-beam sputtering technique. A saturated hall resistivity of about 12.5μΩ.cm at room temperature was observed. The transmission electron microscopy image showed that very small Fe particles of smaller than 1 nm are embedded in Al₂O₃ matrix, and connected into network. The measured ρ - T curve indicated that this giant Hall effect may originate from the percolation phenomenon. With different annealing temperature (T_A) up to 300^oC, the saturated Hall resistivity decreased only a little. The good thermal stability of Fe_45.51(Al₂O₃ )_54.49nano-granular Films showed potential application for magnetic sensor.