Enhanced in-plane ferroelectric polarizations with low in-plane leakage currents in Ca-doped SrBi₂Ta₂O₉ textured ceramics

Aurivillius-phase layered material SrBi₂Ta₂O₉ possesses extremely low leakage current (~10^-9 A×cm^-2) along the out-of-plane direction with in-plane ferroelectricity, which brings in difficulties in achieving high ferroelectric performance and low leakage current simultaneously in the randomly oriented ceramic. Here, highly textured SrBi₂Ta₂O₉ ceramics with texture degree of f = 0.985 are prepared using templated grain growth (TGG) technology with tape-casting method. The in-plane remnant polarization achieves 15.83 μC×cm^-2, which is increased by 197% compared with that of SrBi₂Ta₂O₉ randomly oriented ceramic. Doping Ca elements is found to reduce in-plane leakage current density to J = 5.924 × 10^-7 A×cm^-2, which is attributed to the increased electronic band gap. This research presents an effective route for developing high-performance SrBi₂Ta₂O₉-based ferroelectric device.