Impact of Sr content on dielectric and electrical properties of pulsed laser ablated SrBi2Ta2O9 thin films

The ferroelectric properties of SrBi2Ta2O9 thin films grown by laser ablation were investigated as a function of the Sr+2 content in the films. Different target compositions were used to obtain films with different Sr+2/Ta+5 ratios. The initial composition was according to the stoichiometric composition (1/2), and the Sr+2/Ta+5 ratio was varied to 0.7/2.0. It was seen that the remanent polarization showed a consistent increase, as the film became more deficient of "Sr+2" up to a certain extent. Similarly, a decrease in the dielectric constant and the leakage current with the decrease of Sr+2 in the film was observed. The dielectric transition temperature showed an increase with the reduction of Sr+2 content and was seen to approach the bulk value. (C) 2002 American Institute of Physics.