Magnetic a-Fe2O3, γ-Fe2O3 and Fe3O4 were prepared by facile calcination under different temperature from K4[Fe（CN）6] as raw materials, in which the calcined products are a-Fe2O3, Fe3O4 and y-Fe203 at 400 or 700, 50...Magnetic a-Fe2O3, γ-Fe2O3 and Fe3O4 were prepared by facile calcination under different temperature from K4[Fe（CN）6] as raw materials, in which the calcined products are a-Fe2O3, Fe3O4 and y-Fe203 at 400 or 700, 500, and 600 ℃, respectively. The as-prepared compounds were characterized by X-ray powder diffraction and scanning electron microscopy, and their magnetic behavior at room temperature was also studied. This method provided a simple approach to prepare different polymorphic forms of magnetic iron oxides, which may have potential applications in magnetic science, magnetic composite materials, magnetic core, magnetic separation and medical diagnostics.展开更多
The plane-wave pseudopotential function method, based on density-functional theory, has been used to calculate the adsorption, electronic band structures, orbitals and optical absorption spectrum of [Fe（CN）6]^4- on ...The plane-wave pseudopotential function method, based on density-functional theory, has been used to calculate the adsorption, electronic band structures, orbitals and optical absorption spectrum of [Fe（CN）6]^4- on TiOz anatase（101） surface. Our calculations reveal that the surface-modified anatase system has large adsorption energy and a much narrower band gap. [Fe（CN）6]^4- adsorption on the （101） surface could lead to a large red shift of the anatase optical absorption threshold, which extends into a visible region significantly. The calculated results are in agreement with the experiment and other theoretical studies reasonably. It is very important for the understanding and further development ofphotovoltaic materials that are active under visible light.展开更多
基金supported by the Funds of Fujian province department of education(No.JA14199)
文摘Magnetic a-Fe2O3, γ-Fe2O3 and Fe3O4 were prepared by facile calcination under different temperature from K4[Fe（CN）6] as raw materials, in which the calcined products are a-Fe2O3, Fe3O4 and y-Fe203 at 400 or 700, 500, and 600 ℃, respectively. The as-prepared compounds were characterized by X-ray powder diffraction and scanning electron microscopy, and their magnetic behavior at room temperature was also studied. This method provided a simple approach to prepare different polymorphic forms of magnetic iron oxides, which may have potential applications in magnetic science, magnetic composite materials, magnetic core, magnetic separation and medical diagnostics.
基金the Scientific and Technology Foundation of Fuzhou University and the Key Project of Fujian Province (2005HZ01-2-6)
文摘The plane-wave pseudopotential function method, based on density-functional theory, has been used to calculate the adsorption, electronic band structures, orbitals and optical absorption spectrum of [Fe（CN）6]^4- on TiOz anatase（101） surface. Our calculations reveal that the surface-modified anatase system has large adsorption energy and a much narrower band gap. [Fe（CN）6]^4- adsorption on the （101） surface could lead to a large red shift of the anatase optical absorption threshold, which extends into a visible region significantly. The calculated results are in agreement with the experiment and other theoretical studies reasonably. It is very important for the understanding and further development ofphotovoltaic materials that are active under visible light.
