Hydrothermal Synthesis Of Ferreous Compound Microstructures Materials

Different morphologies of Fe₂O₃ crystal and polyaniline/Prussian blue were prepared by low temperature hydrothermal process. The influence of the experimental parameters on the shapes of the as-prepared a-Fe₂O₃ has been studied. The formation and evolution of this microstructure was investigated by scanning electron microscopy and transmission electron microscopy. Meanwhile, we gave the rational chemical steps for the Prussian blue formation using the single iron-source precursor K₃[Fe(CN)₆] in acidic aqueous solution. The magnetic properties of as-products were discussed.1. Differentα-Fe₂O₃ morphologies from dendritic micro-pines to paired micro-plates, dumbbell, and spindle crystal were prepared. The formation and evolution of this microstructure was investigated by scanning electron microscopy and transmission electron microscopy. A mechanism for the sixfold snowflake-like microstructure to the column-like microstructure transformation has been proposed on the basis of the crystalline structure of the a-Fe₂O₃. Significantly, the magnetic investigations show that the as-obtained a-Fe₂O₃ column-like microstructure exhibited weakly ferromagnetic property at room temperature.2. a-Fe₂O₃ nanospheres of diameters of 100 nm have been prepared under the hydrothermal process using PAM as the stabilizing. The structure and morphologies of the a-Fe₂O₃ nanospheres were characterized by XRD pattern, IR spectrum, EDAX, SEM images and TEM images. The electron diffraction pattern indicated that the a-Fe₂O₃ nanospheres was polycrystalline. At the same time, the influences of the experimental conditions, such as reaction temperature, the concentration of PAM, and the concentration K₃[Fe(CN)₆] on the diameters of the a-Fe₂O₃ nanospheres have been studied. The magnetic property of the a-Fe₂O₃ nanospheres have been investigated.3. Polyaniline/Prussian blue micro-composites have been synthesized by a low temperature hydrothermal process. Prussian blue is obtained using the single iron-source precursor K₃[Fe(CN)₆] in acidic aqueous solution. The composite was characterized by field-emission scanning electron microscopy(FE-SEM), Fourier transmission infrared spectroscopy(FT-IR), and X-ray diffractometer(XRD). The magnetic behavior of Polyaniline/Prussian blue composites and the effect of the concentration of K₃[Fe(CN)₆] on the morphologies of polyaniline/Prussian blue micro-composites have been investigated.