Synthesis and characterization of SrBi2Ta2O9 powders for ferroelectric applications

SrBi2Ta2O9 (SBT) is a bismuth-layered perovskite that finds application as thin film for nonvolatile random-access memories and as high temperature ceramic transducer. The synthesis of SBT by the solid-state reaction requires high temperatures (Tsimilar to1000degreesC), at which bismuth losses are significant, leading to non-stoichiometric compositions with decreased properties. To overcome this drawback, lower temperature reactions of organic precursors have been reported for the production of this oxide. This work describes a novel method to obtain SBT powders that uses Ta2O5 as starting reagent. The thermal behaviour of the SBT precursor gel obtained by this new method is compared to other SBT precursors: those produced by a sol-gel method starting from alkoxides reagents and those related to conventional solid-state reaction. The new method combines the advantage of using reagents that are less toxic and less expensive than alkoxides with the possibility of producing SBT at lower temperatures than those required by the conventional route.