An oxalate–peroxide complex used in the preparation of dopedbarium titanate
Abstract
A method is described for the preparation of homogeneously doped barium titanate, which can be applied in non-linear dielectric elements. Ba and Ti salts are dissolved, mixed with hydrogen peroxide and added to a solution of ammonium oxalate, resulting in the formation of an insoluble peroxo–oxalate complex. The presence of oxalate ions and a high pH are necessary for the formation after calcination of a stoichiometric and sinterable powder. To characterise the structure of the precipitating complex, the thermal decomposition of the complex is studied by means of XRD, d-TGA and FTIR. It is found that the precipitating complex is BaTi0.91Zr0.09O2(C2O4)2H2O. The calcined powder prepared with the peroxo–oxalate method contains no second phase, in contrast to powders prepared with the oxalate method and the peroxide method.