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

Abstract

The hydrothermal synthesis of BaZn _1/3 Ta _2/3 O ₃ has been investigated. Whilst it was relatively straightforward to produce particles having the desired perovskite phase, these particles were deficient in Ba and Zn and correspondingly rich in Ta; some of the excess Zn was precipitated as ZnO. The effects of the metal ion and base concentrations were studied and these were found to affect profoundly the morphology, stoichiometry and crystal structure of the particles. At sufficiently low values of the base concentration, a BaTa ₂ O ₆ type phase was produced instead of the perovskite phase. The data from this study were then used to create a stability diagram showing the regions of stability of the perovskite and BaTa ₂ O ₆ type phases with respect to the base concentration and the total metal ion concentration.