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Abstract: Using low-melting-point Sr(NO3)2 (melting point: 570°C) and high-reactive-activity TiO2 nanocrystals (Degussa P25 TiO2) as the raw materials, phase-pure SrTiO3 nanocrystals were prepared at 600°C. X-ray diffraction and X-ray photoelectron spectroscopy revealed that the as-prepared products were cubic phase SrTiO3 with a surface composition of Sr0.97TiO2.92. Transmission electron microscopy image showed that the as-prepared SrTiO3 comprised nanocrystals with the size of about 24–44nm. UV–vis absorption spectrum of the as-prepared SrTiO3 nanocrystals displayed a wide absorption peak centered at around 365nm (3.4eV), together with a tail at the lower energy side. This kind of low temperature and cost-effective method can also be extended to prepare BaTiO3 nanocrystals, simply by substituting Ba(NO3)2 for Sr(NO3)2. [Copyright &y& Elsevier]

Abstract: A molten salt method was proposed to synthesize SrTiO3 nanocrystals in the eutectic NaCl–KCl at 700°C for 6h, by using the homemade TiO2 nanocrystals and commercial Sr(NO3)2 powder as raw materials. Besides, a control experiment with the commercial TiO2 submicron-sized crystallites as a precursor was also conducted. The structure and composition of the obtained products were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results from XRD and XPS revealed the preparation of pure cubic phase SrTiO3 powders. The TEM observation demonstrated that the nanocrystalline TiO2 precursor played an important role in the current molten salt synthesis of SrTiO3 nanocrystals, which were likely formed by the template formation mechanism. [Copyright &y& Elsevier]