High-temperature and long-term stability in Co/Sb-codoped (Bi0.5Na0.5)TiO3-based electrostrictive ceramics.

• Large electrostrictive response was obtained in modified BNT-based ceramics. • High-temperature and long-term stability was obtained. • The materials have great potential for actuator applications. In this study, we report lead-free Co/Sb-codoped (Bi 0.5 Na 0.5)TiO 3 -based ceramics with enhanced electrostrictive properties and high-temperature and long-term stability. The effect of Co/Sb codoping on the phase structure, electrical properties, and thermal stability of (Bi 0.5 Na 0.5)TiO 3 -based ceramics was studied. The Co/Sb codoping induced the phase transition from the coexisting rhombohedral (R) − tetragonal (T) phase to the single pseudocubic (Pc) symmetry and the disruption of the long-range ferroelectric order of the ceramics, yielding enhanced electrostrictive properties. A large electrostrictive response was obtained in the sample with 0.02 Co/Sb content, with electrostrictive coefficients Q 33 of 0.022–0.024 m4/C2 and electro-strains of 0.35–0.46% under different strengths of the electric field. The electrostrictive material exhibited temperature-insensitive and fatigue-free behavior after up to 105 cycles from room temperature to 120 °C, rendering it a promising material for high-temperature and long-term stability actuator applications. [ABSTRACT FROM AUTHOR]