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Polycrystalline BaBiO3 (BBO) powders were synthesized at different calcined temperature using a solid state reaction method. X-ray diffraction analysis confirms that the compounds are a monoclinic structure with space group C2/m. The average particle size increases with the increasing synthesized temperature observed by scanning electronic microscopy. The band gap of the powder is calculated to be about 1.8 eV according to the absorption edge of 620 nm. The surface photovoltage spectroscopy reveals that the powder demonstrates two strongest surface photovoltage response peaks at 400 and 470 nm, which may be due to the surface states caused by the defects and oxygen vacancies in the band gap. The photoluminescence spectra show that the recombination rate of the photo-carriers decreases with the increase of synthesized temperatures, correspondingly, the intensity of the emission spectra decreases. In addition, the strong photocatalytic decoloration effect on methylene blue could further corroborate photo-generated carriers behavior in the BBO powders. [ABSTRACT FROM AUTHOR]

Abstract: Coatings with a thickness of 22–32μm were formed on an AM60B magnesium alloy by plasma electrolytic oxidation (PEO) in electrolytes containing 12.0–24.0g/l NaAlO2 and other additives. SEM analyses of the coated samples showed that the coatings were compact with relatively low porosity. X-ray diffraction revealed that the coatings consisted of mainly MgAl2O4 and MgO phases. The relative amount of MgAl2O4 in the coating increased with increasing NaAlO2 concentration. The relatively compact and thick coatings provide good corrosion protection for magnesium, as indicated by the results of potentiodynamic polarization tests. In addition, the PEO treatment also significantly improved the wear resistance of the alloy. Pin-on-disk wear tests showed that the PEO treatment reduced the wear volume loss by a factor of 10. [Copyright &y& Elsevier]

Abstract: A Al2O3 coating was prepared on titanium substrate by cathodic microarc electrodeposition method in Al(NO3)3 ethanol solution. The coating thickness was about 80μm when a 400V cathodic potential was applied. The morphology and phase constituent of the Al2O3 coating were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The isothermal oxidation at 700°C and electrochemical corrosion behavior of the coated titanium were analyzed. The coating was composed of γ-Al2O3 and little α-Al2O3 phases. The oxidation resistance of the titanium subjected to cathodic microarc treatment was obviously improved. The polarization test indicated that the coated titanium has better corrosion resistance. [Copyright &y& Elsevier]