Electrical transport, magnetic properties of the half-metallic Fe3O4-based Schottky diode

Fe3O4 thin films were prepared successfully by using the rf-sputtering technique with Fe2O3 target. The inverse spinel structure of the film was determined by X-ray diffraction (XRD) and the single phase of the Fe3O4 was confirmed by the XPS measurements. The surface roughness increases with the increase of the partial pressure of hydrogen. A high saturated magnetic field, 5000 Oe, implies that there exist the antiphase boundaries (APBs) in the film. The higher coercive filed below TV is ascribed to the lower symmetry of the monoclinic structure. The temperature dependence of resistance shows a very clear Verwey transition and it is implied that the electrical transport behavior follows the variable-range hopping (VRH) mechanism from 40 to 300 K. The current vs. voltage curves of Fe3O4/Si Schottky heterojunction exhibits good rectifying property. The ideality factor and Schottky barrier height were obtained from the fitting curves calculated by the standard thermionic emission/diffusion model.