Synthesis of Fe3O4 Nanowire Arrays Via Precipitation in Templates and Microwave Hydrothermal Process

Template growth of Fe3O4 nanowire arrays via precipitation and subsequent microwave hydrothermal process was investigated. Anodic aluminum oxide and polycarbonate templates were immersed in a ferrous chloride and ferric chloride mixture and the precipitation of Fe3O4 took placed by adjusting the solution to pH>9. A microwave hydrothermal process was subsequently performed at 150 degrees C for 30 min in order to further enhance the crystallinity of the Fe3O4 nanowires. The length of the nanowires is about 5-20 mu m and the diameter is about 220 nm, with perfect surface finishing. The nanowires were polycrystalline cubic spinel structures and composed of nanometer-sized particles, as characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Magnetic properties in parallel and perpendicular direction were measured using a vibrating sample magnetometer, where the magnetization in the perpendicular direction of the nanowires is higher than that of the parallel direction. Microwave hydrothermal treatment improved the crystallinity and morphology of Fe3O4 nanowires and resulted in a much better magnetization than that without microwave hydrothermal treatment.