Hydrothermal synthesis and characterisation of perovskite BaZn1/3Ta2/3O3

The hydrothermal synthesis of BaZn1/3Ta2/3O3 has been investigated. Whilst it was relatively straightforward to produce particles having the desired p erovskite phase, these particles were deficient in Ba and Zn and correspond ingly rich in Ta; some of the excess Zn was precipitated as ZnO. The effect s of the metal ion and base concentrations were studied and these were foun d to affect profoundly the morphology, stoichiometry and crystal structure of the particles. At sufficiently low values of the base concentration, a B aTa2O6 type phase was produced instead of the perovskite phase. The data fr om this study were then used to create a stability diagram showing the regi ons of stability of the perovskite and BaTa2O6 type phases with respect to the base concentration and the total metal ion concentration.