Structural and dielectric properties of Ba0.7Sr0.3TiO3 thin films grown by PLD

Ferroelectric thin films of Ba0.7Sr0.3TiO3 (BST) were deposited on Si/SiO2/TiO2/Pt (PtSi) substrate by pulsed laser deposition (PLD). Crystalline films with perovskite structure were obtained without post-deposition annealing. Phase purity of the deposited films was confirmed by x-ray diffraction. The lowest value of FWHM obtained for the film deposited at oxygen pressure 5.4×10−4 mbar and substrate temperature 600°C, indicates the high crystallinity of the film. The room temperature dielectric constant at 100 kHz was 85. Butterfly loop, which is the characteristic of ferroelectric materials, was obtained in the regime of −4 to +4V. The leakage current density was nearly 9×10−13 Acm−2.