Doping characterization studies of layered perovskite SrBi₂Ta₂O₉ ferroelectric thin films

The characterization of Nb-doped layered perovskite SrBi₂Ta₂O₉ was studied. The mechanism of modification of properties was analyzed. Photoacoustic spectroscopy has been used to study the light absorption of SrBi₂Ta₂O₂ with various Nb contents. The results show that the absorption band at 580 nm in the photoacoustic spectroscopy exhibits a red shift with increasing niobium content. The remanent polarization of Nb-doped SrBi₂Ta₂O₉ films depends on the concentration ratio of Ta/Nb. The remanent polarization of the films arose an maximum at the area of Ta/Nb ≈ 1. This may be related to the existence of morphotropic phase boundary.