Large electric field-induced strain near AFE/FE phase boundary in (Pb0.97La0.02)(Zr, Sn, Ti)O3 system

(Pb0.97La0.02)(Zr, Sn, Ti)O3 ceramics were prepared by conventional solid state reaction process, and the effects of Zr4+/Sn4+ and Zr4+/Ti4+ ratios on the crystal structure, dielectric, ferroelectric, and electric field-induced strain properties were systemically investigated. The XRD results showed, with the increase of Zr4+ and Ti4+ contents, the stability of the specimens became weakened and a transformation from AFE to FE phase was observed at x = 0.65 and y = 0.12, respectively. In addition, it was observed that the strain first increased with a maximum value in the composition near AFE/FE phase boundary, and then decreased with increasing Zr4+ and Ti4+ contents. Further, with the decrease of measuring frequency, the strain continuously increased because the reversal of the domain can be more sufficient. The maximum strain of 0.55 % is obtained in Pb0.97La0.02(Zr0.63Sn0.26Ti0.11)O3 AFE ceramics at 1 Hz measuring frequency which lays a foundation for preparing actuators with high properties.