Effect of annealing temperature on the electrostrictive properties of 0.94(Na0.5Bi0.5)TiO3-0.06BaTiO3 thin films

0.94(Na0.5Bi0.5)TiO3-0.06BaTiO3 (NBT-BT6) thin films were fabricated by metal-organic decomposition (MOD) at the different annealing temperatures. Based on the electrostrictive effect and converse piezoelectric effect, the phenomenological approach is provided to characterize the electrostrictive properties of the perovskite relaxor, and it is used to determine the effective electrostriction coefficients $$ Q₃₃^{\mathrm{eff}} $$ and electrostrictive strains $$ {S_3} $$ of NBT-BT6 thin films annealed at the range of 650–800 °C. After the microstructure, ferroelectric, dielectric and piezoelectric properties of the thin films were determined, the maximum values of $$ Q₃₃^{\mathrm{eff}} $$ and $$ {S_3} $$ of NBT-BT6 thin film annealed at 750 °C are respectively determined as 0.0289 m4/C2 and 0.26 % under the bipolar driving field of 391 kV/cm. They are strongly influenced by annealing temperature due to the bismuth evaporation and crystallization of perovskite phase, and the enhanced electrostrictive properties could make NBT-based thin film a promising candidate to the design and application of stacked actuators, microangle-adjusting devices, and oil pressure servo valves.