Preparation of cauliflower-like shaped Ba_(0.6)Sr_(0.4)TiO_3 powders by modified oxalate co-precipitation method

摘要

The quantitative barium-strontium titanyl oxalate (Ba_(0.6)Sr_(0.4)TiO(C_2O_4)_2 centre dot 4H_2O, BSTO) precursor powders were prepared by the modified oxalate co-preparation method. It was based on the cation-exchange reaction between the stoichiometric solutions of oxalotitanic acid (H_2TiO(C_2O_4)_2, HTO) and barium + strontium nitrate solution containing stoichiometric quantities of Ba and Sr ions. The pyrolysis of BSTO at 800 deg C/4 h in air produced the homogeneous cauliflower-like shaped barium-strontium titanate (Ba_(0.6)Sr_(0.4)TiO_3,BST) powders. The effect of polyethylene glycol (PEG) on morphology of BSTO and BST powders was also investigated. The characterization studies were carried on the as-dried BSTO and calcined BST powders by various physicochemical techniques, IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), etc. The BSTO and BST powders obtained by aforementioned technique without PEG were homogeneous with spherical shape. The particles grew into spindle shape with the effect of PEG.