Improving the synthesis and properties of SBT thin films by using SBT seeds

Among the different materials studied for ferroelectric applications, SrBi2Ta2O9 (SBT) and SrBi2Nb2O9 (SBN) have deserved a particular interest for the production of non-volatile random access memories (NVFRAMs) due to their fatigue endurance properties. However, the high temperatures required for obtaining these Aurivillius compounds in a straightforward way make necessary to search alternative procedures to synthesize them. In this work the approach of using SBT seeds to improve the synthesis of SBT thin films by a sol-gel procedure is studied and their effects on the thin film properties are evaluated. XRD and SEM analysis of the obtained seeded and unseeded thin films, annealed at different temperatures, show that the use of SBT seeds lowers the crystallization temperature of the perovskite phase and affects the thin film microstructure inducing the development of well defined and more elongated grains. Dielectric and ferroelectric properties are also improved by the seeding procedure. The characteristics of the seeded films annealed at 720 °C for 20 min show that the present technique has the advantage of requiring smoother annealing conditions than currently reported methods for producing films with comparable characteristics.