Lead-free (K_0.5-x/2Na_0.5-x/2Li_x)(Nb_0.8Ta_0.2)O₃ (KNLNT) and (K_0.49-x/2Na_0.49-x/2-Li_xCa_0.01)(Nb_0.8Ta_0.2)O₃ (KNLNT-Ca) ceramics were prepared by a conventional ceramic processing. Structural analysis shows that the Ca²⁺ doping takes the A site of ABO₃ perovskite and decreases the phase transition temperature. Property measurements reveal that as a donor dopant, the Ca²⁺ doping results in higher room-temperature dielectric constant, lower dielectric loss, and lower mechanical quality factor. In addition, the Ca²⁺ doping does not change the positive piezoelectric coefficient d₃₃, but increases the converse piezoelectric coefficient d₃₃^* significantly. This is likely due to the increase in the relaxation, as well as the appearance of (Ca_Na/K·-V_Na/K’) defect dipoles.

无铅（K _{0.5- x / 2} Na _{0.5- x / 2} Li _x）（Nb _0.8 Ta _0.2）O ₃（KNLNT）和（K _{0.49- x / 2} Na _{0.49- x / 2} -Li _x Ca _0.01）通过常规陶瓷加工制备（Nb _0.8 Ta _0.2）O ₃（KNLNT-Ca）陶瓷。结构分析表明，Ca ²⁺掺杂占据了ABO ₃的A位点钙钛矿并降低相变温度。性能测量表明，作为施主掺杂剂，Ca ²⁺掺杂导致较高的室温介电常数，较低的介电损耗和较低的机械品质因数。另外，Ca ^2+的掺杂不会改变正压电系数d ₃₃，反而会显着增大逆压电系数d ₃₃ ^*。这可能是由于弛豫的增加以及（Ca _{Na / K} ·-V _{Na / K} '）缺陷偶极子的出现。