Simple oxalate precursor route for the preparation of brain-like shaped barium–strontium titanate: Ba 0.6Sr 0.4TiO 3

Abstract

Through adding quantitative ammonia into a precursor solution containing stoichiometric quantities of Ba and Sr ions before the co-precipitation procedure, a simple oxalate co-precipitation method based one-step cation-exchange reaction between the stoichiometric solutions of oxalotitanic acid (HTO) and barium + strontium nitrate is investigated successfully for the quantitative precipitation of barium–strontium titanyl oxalate (BSTO): Ba 0.6Sr 0.4TiO(C 2O 4) 2·4H 2O precursor powders. The pyrolysis of BSTO at 800 °C/4 h in air produced the homogeneous brain-like shaped barium–strontium titanate (Ba 0.6Sr 0.4TiO 3: BST) powders. The characterization studies were carried on the as-dried BSTO and calcined BST powders by various physicochemical techniques, IR, DSC/TGA, XRD, SEM, etc. It revealed that the BST powders are cubic, stoichiometric, highly pure, sub-micron-sized with nearly uniform size, brain-like shape and agglomerated nature.