Magnetic properties of Fe3O4 nanostructures

In this research, nano-dot array with magnetite (Fe₃O₄) nanoparticles using an anodized aluminum oxide (AAO) nanotemplate is produced. The hexagonally ordered nanotemplates are created using a two-step anodization method. After a pore-widening process of the nanotemplates, the 10 nm nanoparticles are inserted by magnetic stirring method. Annealing of the nanostructures at 500°C for 1 hr is done. Surface and cross-section of the template filled with nanoparticles are observed by field emission scanning electron microscopy (FESEM). At as-filled state, the nanostructure shows low coercivity of 20 Oe but after annealing, it increased to 85 Oe. The magnetic properties of nano wires consisting of nanoparticles are improved due to recrystallization and grain growth of each magnetic particles and their structure may be changed due to agglomeration.