Effect of CuO on dielectric and piezoelectric properties of (K0.4425Na0.52Li0.0375)(Nb0.87Ta0.06Sb0.07)O3 ceramics

In this paper, the effects of CuO addition on microstructure and electrical properties of (K0.4425Na0.52Li0.0375)(Nb0.87Ta0.06Sb0.07)O3 (abbreviated as KNLNST) ceramics were studied to develop KNLNST with high mechanical quality factor Qm and low dielectric loss tan δ. The results of this work suggest that both “hard” and “soft” effects were observed due to CuO addition, which enhanced the Qm and planar mode electromechanical coupling factors kp, and reduced the piezoelectric coefficient d33, coercive field Ec, dielectric constant ɛr and tan δ. High dielectric and piezoelectric properties of ɛr = 1304, d33 = 241 pC/N, kp = 0.437 and Qm = 138 were obtained for the specimens containing 1 mol% CuO. Particularly, tan δ at 1 kHz can be reduced from 0.038 for KNLNST ceramics to 0.0087 for 1 mol% CuO-added KNLNST ceramics.

► We studied the effects of CuO addition on microstructure and electrical properties of KNN-based ceramics.
► The results of this work suggest that both “hard” and “soft” effects were observed due to CuO addition.
► CuO addition enhanced the Qm and planar mode electromechanical coupling factors kp, and reduced the piezoelectric coefficient d33, coercive field Ec and tan δ.
► Particularly, tan δ at 1 kHz can be reduced from 0.038 for undoped ceramics to 0.0087 for 1 mol% CuO-doped ceramics.