Large electric field induced strain in a new lead-free ternary Na0.5Bi0.5TiO3-SrTiO3-BaTiO3 solid solution

The new lead-free ternary system (0.8-x)NBT-0.2ST-xBT prepared by solid state reaction with 100%perovskite phase, undergoes a structural change from pseudo-cubic (x≤0.04)to tetragonal (x≥0.06)along with a possible phase coexistence between 0.04≤x≤0.06. At x=0.04, the solid solution exhibits an optimum dielectric constant εmax of 2670, a strong relaxor behavior with a high diffuseness coefficient close to 2evidenced by slim P-E loops, excellent piezoelectric properties such as optimum strain value Smax of 0.424%and a normalized piezoelectric constant d33*of 688pm/V. The above encouraging results may be helpful for further investigations of NBT-ST based ternary systems in search of a potential Pb-free piezoelectric material. [Display omitted] •A new Pb-free relaxor (0.8-x)NBT-0.2ST-xBT ternary solid solution is prepared.•A MPB around 0.04BT is anticipated between pseudocubic and tetragonal phases.•Large Smax=0.424% and d33*=688pm/V at a low driving field of 6kV/mm is achieved.•Role of defect dipoles in obtaining recoverable strain is highlighted.•Strong relaxor behavior, large d33* and Smax are suitable for actuator application.