Papers by Keyword: Perovskite-Type

Abstract: The 0.94Bi_0.5Na_0.5TiO₃-0.06BaTiO₃ (abbreviated to BNT-BT) powder and ceramic was synthesized by sol-gel process. The phase structure and dielectric properties of the ceramics were investigated. The ceramic was sintering at 1000-1100 degree C for 2-4 h in air atmosphere, and the X-ray diffraction (XRD) results revealed that the samples was pure perovskite-type phase. The Curite temperature of BNT-BT ceramics was high up to 348 degree C. The temperature dependence of dielectric permittivity and loss revealed there were two phase transitions, which were from ferroelectric (tetragonal) to anti-ferroelectric (rhombohedral) and anti-ferroelectric to paraelectric (cubic) in BNT-BT ceramics. Diffuse phase transitions were observed in BNT and BNT-BT ceramics and the Curie-Weiss Exponent (CWE) were nearly 2.

Abstract: A series of rare earth perovskite-type oxides La0.9Sr0.1CoO3, La0.9Sr0.1MnO3 and La0.9Sr0.1Co0.5Mn0.5O3 were prepared by sol-gel method and characterized by X-ray diffraction (XRD), specific surface analysis (BET), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) techniques. The results showed that for La0.9Sr0.1Co0.5Mn0.5O3 sample, Sr2+ and Mn3+ ions partly replaced La3+ and Co3+ ions and entered perovskite crystal lattice, and finally a perfect crystal structure of perovskite was formed. Moreover, these powders presented sphericity granules with particle size of about 20nm and satisfactory pore structure. With the doping of Sr2+ ions in a certain range, the coexisting system of Mn3+- Mn4+ and Co3+- Co4+ as well as the concentration of oxygen vacancies were increased, thus leading to the higher catalytic activity of the prepared catalysts.

Abstract: Photocatalyst of perovskite type V-doped titanium-bearing blast furnace slag (VTBBFS) were prepared by high temperature solid-state method with different concentration of V for 2 hours at 800°C. The structure and composition of VTBBFS photocatalyst was characterized by XRD, UV-vis absorption spectra, and SEM images. It shows that VTBBFS photocatalyst has perovskite structure, and a kind of irregular and massive particles by calcined at 800°C. Its photo absorption performance was checked by UV-Vis spectrophotometer, its absorption spectrum has a obvious red shift. Use Aspergillus Niger to research the antibacterial activities of VTBBFS photocatalyst. The results show the antibacterial activities of VTBBFS photocatalyst has a good antibacterial performance with 5% diluent of VTBBFS15 under the UV light.