Magnetic-field-induced formation of one-dimensional magnetite nanochains.

Magnetite nanoclusters with an average size of about 120 nm have been prepared and allowed to self-assemble into one-dimensional (1D) nanochain structures with the average length about of 2 mum by a simple magnetic-field-induced (MFI) assembly approach (0.20 T). The constituent, phase, and morphology of these 1D nanochains have been characterized by X-ray diffraction and transmission electron microscopy. Magnetic measurement reveals that these 1D nanochains are weakly ferromagnetic at room temperature. In this paper, we discuss the influence of magnetization time and strength of external magnetic field on the formation of 1D nanochains. We also show that, by changing the amount of hydrogen peroxide in the starting materials, 1D nanochains with different interparticle spacing can be obtained. This 1D nanochain structure with different interparticle spacing would be an ideal system for the further study of magnetization properties of 1D ordered magnetic nanostructures.