The sintering aids maintain giant strain in lead‐free NBT‐ST piezoceramics sintered at 975oC

The 0.74Na 1/2 Bi 1/2 TiO 3 –0.26SrTiO 3 codoped with Li 2 CO 3 and B 2 O 3 is studied to develop the low‐temperature sintered lead‐free piezoceramic for multilayer applications. The studied piezoceramics are synthesized by a conventional solid‐state reaction method. Their crystal structures, microstructures, ferroelectrics, and strain properties are analyzed. Interestingly, the addition of Li 2 CO 3 and B 2 O 3 reduces the sintering temperature of the 0.74Na 1/2 Bi 1/2 TiO 3 –0.26SrTiO 3 sample from 1175 to 975 °C. All samples show a pseudocubic perovskite structure with a dense microstructure and an inhomogeneous grain size distribution. The electric‐field‐induced polarization loops of the samples are saturated at 4 kV mm −1 . More importantly, the 0.74Na 1/2 Bi 1/2 TiO 3 –0.26SrTiO 3 + 1 wt%Li 2 CO 3 + 1 wt%B 2 O 3 sample sintered at 975 °C shows a S max / E max value of 510 pm/V under an applied electric field of 2 kV mm −1 , which is promising for multilayer lead‐free piezoelectric actuator applications.