Co-doping Ce3+ and Mn4+ to induce pseudo tetragonal distortion in CaBi2Nb2O9 for improved piezoresponse

Calcium bismuth niobate (CBN), known for its high Curie temperature ( T C ), has been investigated as a potential material for vibration sensor due to its ability to operate at elevated temperatures. However, the inherent weakness in piezoresponse of CBN has limited its sensing performance. In this study, a pseudo-tetragonal distortion in CBN was successfully induced by incorporating Ce 3+ ions into the (Bi 2 O 2 ) 2+ layers of CBN. This modification led to a change in the interaction between the perovskite and bismuth layers, resulting in enhanced piezoelectric and ferroelectric properties. Further enhancement was achieved by introducing Mn 4+ ions into the Ce 3+ -doped CBN. The co-doped CaBi 1.96 Ce 0.04 Nb 1.985 Mn 0.015 O 9 demonstrated a significantly improved piezoelectric coefficient ( d 33 ) of 15.9 pC/N, compared to 6.8 pC/N for pure CBN ceramics, and an increased remnant polarization ( P r ) of 20.78 μC/cm 2 , compared to the 3.83 μC/cm 2 of the pure material. This work not only deepens the understanding of bismuth-layer-structured ferroelectrics (BLSFs) but also presents a viable co-doping strategy to enhance the piezoresponse in CBN ceramics. This strategy could pave the way for the development of high-performance, high-temperature vibration sensors and potentially lead to the discovery of more novel BLSFs with superior performance.