In this study, a-/b-axis-oriented epitaxial Sr0.8Bi2.2Ta2O9 (SBT) thin films were grown on (101)TiO2 and (101)RuO2//(110)Al2O3 substrates by metalorganic chemical vapor deposition (MOCVD). By several X-ray diffraction techniques, the a-/b-axis-oriented epitaxial growth on the substrate with a rutile structure was confirmed. The leakage current density of SBT was characterized along the a-/b-axis and c-axis, and the lower defect density in the pseudoperovskite layer was revealed by comparison with Bi4Ti3O12. The saturation polarization (Ps), remanent polarization (Pr), and coercive field (Ec) were 6.0μC/cm2, 3.1μC/cm2 and 54 kV/cm, respectively. The estimated spontaneous polarization along the a-axis corrected by the a-/b-domain volume ratio was 20μC/cm2, which is identical to previously estimated values. The switching charge versus the repetitive 1.2×1010 switching cycles remained almost constant, indicating a superior fatigue endurance along the direction parallel to the (Bi2O2)2+ layer.
- Bismuth layer-structured ferroelectrics
- Epitaxial film
ASJC Scopus subject areas
- Physics and Astronomy(all)