Effect of La doping on structure and dielectric properties of PLZST antiferroelectric ceramics

For the ABO₃ perovskite structure in PZT-based antiferroelectrics, the cations with different radii at A or B position will affect the phase structure of the material. In this paper, the effect of La on the phase structure, dielectric property and field-induced phase transformation of PZT-based ceramics was studied by replacing Pb²⁺ with smaller ions La³⁺ with the formula of (Pb_1−3x/200La_x/100)(Zr_0.75Sn_0.16Ti_0.09)O₃ ceramics (x = 0, 2, 4 and 6) and all samples were prepared through conventional solid-phase reaction sintering. It was found that the samples were ferroelectric rhombohedral phase with x = 0 and turned into an antiferroelectric tetragonal phase with increasing La content. Higher forward/backward switching fields and smaller hysteresis were achieved with increasing La content. The results also indicated proper content of La could effectively enhance the stability of antiferroelectric in this PZT-based antiferroelectric. Furthermore, the released energy density and energy storage efficiency were improved as the La content increased, reaching a maximum of 3.45 J/cm³ and efficiency of 91.3% when x = 0.06. It can be reasonably concluded that La doping can tailor the electric properties in PZT-based energy storage materials. For L4, as the field strength approaches the switching field, the I_max/E and the released charge also increase significantly.