Synthesis and Characterization of Barium Strontium Titanate Nanocrystalline Powders Prepared by Direct Reactive Precipitation Method from Solution

Abstract

Barium strontium titanate nano powders were prepared by mixing ethanol solution of tetrabutyl titanate with an aqueous solution of Ba(OH)2•8H2O and Sr(OH)2•8H2O with a certain molar ratio of barium to strontium at 40°C－95°C. The products were characterized by thermogravimetry (TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM) and atomic force microscopy (AFM). The results show that the powders prepared with the reactant concentration of 0.8M are spherical in particle shape with the grain size of 50nm－65nm. When the annealing temperature of the powders is higher than 906°C, the hydroxyl groups existed in barium strontium titanate lattice are removed. XRD analysis demonstrate that the as-prepared powders are cubic phase. All the diffraction peaks are shifted towards higher diffraction angles and the lattice parameter a calculated decreases linearly with serial decrease of the molar ratio of barium to strontium.

Synthesis of Hollow Ba_0.7Sr_0.3TiO₃Nanocubes by Using Molten Hydrated Salt as a Solvent

“…As above-described XRD analysis, the primary crystallites in the Ba 0.7 Sr 0.3 TiO 3 particles obtained at 180 ˚C for 15 h have an average size of 22 nm, which can verify the aggregation characteristic of the Ba 0.7 Sr 0.3 TiO 3 particles. Further MHS treatment would result in the inside-out ripening of the particles [12,[14][15][16]. The smaller or loosely packed Ba 0.7 Sr 0.3 TiO 3 crystallites inside the particles would dissolve and diffuse outward.…”