Enhanced ferroelectric and piezoelectric properties of Sb/Nb co‐doped BiScO3-PbTiO3-based ceramics via relaxation regulation near morphotropic phase boundary

Here, novel ferroelectric ceramics of Sb/Nb co-doped 0.36BiScO3-0.64PbTiO3 (BS-PT-Sb2O5-xNb2O5) of complex perovskite structure are reported with compositions near the morphotropic phase boundary (MPB) where the dominant monoclinic and tetragonal phases coexist. Excitingly, the incorporation of Sb/Nb dopants leads to a remarkable enhancement in both ferroelectric and piezoelectric properties. Notably, the sample with x=1.0 demonstrates the optimal properties, boasting a giant piezoelectric coefficient (d33) of 498 pC/N (10.7% higher than pure BS-PT ceramics), a high Curie temperature (Tc) of 392°C, a high depolarization temperature of 362°C and a large remanent polarization of 52.7 μC/cm2 (55.9% higher than pure BS-PT ceramics). The enhanced ferroelectric and piezoelectric properties are ascribed to a relaxation behavior originating from the formation of polar nanoregions (PNRs) and reduced concentration of oxygen vacancy. The result provides an opportunity to elucidate the relationship between relaxation behavior and electrical properties, offering prospects for substantially improving the performance of piezoelectric ceramics.