High coercivity in α-FeO32 nanostructures synthesized by surfactant-free microwave-assisted solvothermal method

In this report, the cube-like shaped α-Fe2O3 nanostructures were prepared by the simple microwave-assisted solvothermal method without using any surfactants. The as-prepared samples were characterized by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The well dispersed and size-controlled cubic-like shaped α-Fe2O3 nanostructures were obtained by systematic variation of solvents, reaction temperature and time. The magnetic studies manifest that the magnetic properties of α-Fe2O3 samples are strongly dependent on the shape and size of the nanostructures. The maximum coercivity (Hc) ∼ 5.6 kOe is observed for Fe-160-30 sample, which is originating from the varying synthesis conditions, oriented sub-particle structures, surface spin disorder, surface/interface anisotropy and interactions of the nanoparticles at the surface/interface of the nanostructures. Represented synthesis approach facilitates the preparation of nanostructured materials with controlled morphology and properties.
Source: Physics Letters A - Category: Physics Source Type: research