Deciphering the synergistic action of multiple factors inducing high piezoresponse in CaBi₄Ti₄O₁₅-based piezoelectric ceramics

NaBiCe/Sc ions were co-doped into a pure CaBi4Ti4O15 (CBT) ceramic to investigate the synergistic action of multiple factors that induced a high piezoresponse. In comparison to the undoped CBT ceramic, the NaBiCe/Sc co-doped CBT solid solution exhibited an enhancement in spontaneous polarization (P-s) attributed to the tilting of the oxygen octahedra, enhanced domain reorientation owing to increased grain size, and improved dielectric breakdown strength as a consequence of reduced porosity. The synergistic action of the aforementioned comprehensive factors resulted in excellent electrical properties of Ca-0.6(Na0.5Bi0.5)(0.4)Bi3.97Ce0.03Ti3.925Sc0.075O15 ceramic: piezoelectric coefficient d(33) = 25.0 pC/N, remnant polarization P-r = 9.28 mu C/cm(2), and coercive field E-c = 76.14 kV/cm. Moreover, a significant high direct current resistivity (rho(dc) = 1.22 x 10(7) Omegacm at 500 degrees C) was achieved, and the corresponding conductance mechanism was analyzed through a synergistic approach that combines ultraviolet-visible diffuse reflectance spectra and density functional theory.