Synthesis of CoFe₂O₄ nanotube arrays through an improved sol-gel template approach

Self-organized and ordered CoFe₂O₄ nanotube arrays were prepared in porous anodic aluminum oxide template using an improved sol-gel approach. The attraction between the negatively charged sol particles and the positively charged pore wall of AAO is the causation of tube formation process. The morphology was studied by transmission electron and high-resolution field emission scanning electron microscope. A polycrystalline phase of the nanotube was found by X-ray and select area electron diffraction. Magnetic measurements showed that the magnetic orientation was weak in the arrays of nanotube, and the reason has been discussed.