Solid phase preparation of submicron-sized SrTiO3 crystallites from SrO2 nanoparticles and TiO2 powders

Submicron-sized SrTiO₃ crystallites were prepared by a low temperature solid state method. The proposed preparation method involved two simple steps: firstly, SrO₂ nanoparticles of 35–90 nm were precipitated from the reaction of Sr(NO₃)₂ and H₂O₂ in an alkalescent aqueous solution (pH = 8) under the ambient condition; secondly, perovskite phase SrTiO₃ with a minor amount of SrCO₃ impurity were produced by heating the mixture of excessive SrO₂ nanoparticles and commercial TiO₂ powders in air at 700 °C for 10 h, which could be easily washed with 1 mol/l HNO₃ aqueous solution and distilled water to yield pure SrTiO₃ crystallites with the size of about 125–320 nm. The phase, purity and size of the as-obtained product were characterized by means of powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM).