Piezoelectricity, thermal stability, and fatigue resistance in Nb and Ta-doped Bi4Ti3O12 high-temperature piezoceramics.

The effect of Nb/Ta donor doping on the piezoelectricity, thermal stability, and fatigue resistance of bismuth titanate Bi 4 Ti 3 O 12 (BIT) ceramics was investigated in relation to their structural and oxygen vacancy-related electrical properties. As the Nb/Ta doping amount increased, the activation energy of oxygen vacancy conduction increased, indicating a reduction in the concentration of oxygen vacancies. The improved electrical insulating properties of the Nb/Ta-doped Bi 4 Ti 3 O 12 ceramics (BTNT) with fewer oxygen vacancies, contributed to their effective poling and strong piezoelectricity. Outstanding piezoelectric performance with high piezoelectric constant (39 pC/N) and Curie temperature (690 °C) could be achieved in the 0.005 mol Nb/Ta-doped BTNT ceramic with high density and anisotropic grain growth. The BTNT ceramics exhibited superior thermal aging stability and fatigue resistance compared to the BIT ceramic, suggesting that the reduction of oxygen vacancy defects plays a decisive role in enhancing elevated-temperature-induced and electric-field-induced degradation stabilities. [ABSTRACT FROM AUTHOR]