High-resolution electron microscopy investigations on stacking faults in SrBi₂Ta₂O₉ ferroelectric thin films

Abstract

Structural planar defects in the SrBi2Ta2O4 (SBT) films with 10 mol% excess Bi grown in Pt/TiO2/SiO2/Si substrates by metalorganic deposition have been observed by high-resolution electron microscopy. It was found that these stacking defects were planar defects with extra Bi-O planes normal to the c axis. These structural defects are expected to effectively improve the ferroelectric response and fatigue-resistance characteristics of SBT films because of the extra Bi-O planes having higher strucutral flexibility and alleviating the mechanical stresses and strains as well as injected-charge problems.