a-Axis growth of ferroelectric SrBi2Ta2O9 thin films on silicon

By using SrZrO3/(Y2O3)x(ZrO2)1−x buffer layers, it is possible to obtain a-axis oriented SrBi2Ta2O9 thin films on silicon by laser deposition. Using evanescent wave X-ray measurements, we show that at lower deposition pressures the films present two phases with up to 25% a-axis and the rest (116) orientation. At higher pressures, the a-axis orientation is only obtained for larger energies per pulse of the irradiating laser. From our results, we expect that further optimisation in the degree of a-axis orientation can be achieved.