Low Temperature Preparation of Strontium Barium Niobate Powders by the Aqueous Organic Gel Method

SrxBa1-xNb2O6(x=0.5) ceramic powders were synthesized by the aqueous organic gel routes. The desired metal cations were chelated in a solution by using citric acid and ethylenedi-aminetertraacetic acid (EDTA) as the chelating agents. The thermal decompostion of the metal carboxylate precursor gels was studied by TG/DTA and the products derived from calcinations of the gels at different temperatures were characterized by XRD and TEM. The results reveal that tetragonal tungsten bronze-type structural SBN with fine particle size can be achieved at 8008℃. The influences of pH and molar ratio of citric acid: Nb cation on the formation of homogeneous Sr-Ba-Nb precursor gels were also studied. pH=8 used during the preparation of Sr-Ba-Nb precursor gels was determined by calculation of the conditional formation constant Kcf of Sr-EDTA and Ba-EDTA complexes.