Ferroelectric properties of Pr and Nb co-substituted Sr0.8Bi2.2Ta2O9 thin films

Thin film of both A- and B-site co-substituted Sr0.8Bi2.2Ta2O9 (SBT) by Pr3+ and Nb5+, i.e. Sr0.8Pr0.1Bi2.1Ta1.5Nb0.5O9 (SPBTN) was fabricated on Pt/Ti/SiO2/Si substrates by metalorganic decomposition method. The Nb5+ substitution at B-site and Pr3+ substitution at A-site enhanced the remanent polarization and reduced the coercive field of the films, respectively. The remanent polarization (2Pr) value of the SPBTN film was 22 μC/cm2. The coercive field (2Ec) value of the SPBTN film was 102 kV/cm, which was much lower than that of SBTN (165 kV/cm). The effects of substitution on structural and ferroelectric properties of SBT were discussed in detail. As a result, the A- and B-sites co-substitution may be one of the promising ways to improve ferroelectric properties of SBT.