Effect of crystal structure on the improvement of the piezoelectric properties for [001]-textured PZT-PNN piezoceramics

Ceramics with a coexisting rhombohedral-tetragonal (R-T) structure, 0.53 Pb(Zr1-xTix)O3-0.47 Pb(Ni1/3Nb2/3)O3 [CP(Z1-xTx)-PNN] (x = 0.57 and 0.66) containing 1.0 mol% CuO, are textured along the [001] direction using BaTiO3 (BT) templates. The CP(Z1-xTx)-PNN ceramics achieve effective [001] texturing at 1250 °C, as evidenced by a high Lotgering factor (>94%) utilizing 3.0 vol% BT templates. CuO reduces the sintering temperature but does not assist in the texturing of the specimen at low temperatures. Adding a large amount of BT templates reduced the piezoelectric properties of the specimens. The study reveals untextured CP(Z0.43T0.57)-PNN ceramic with low d33 (370 pC/N) and kp (0.49) values exhibiting substantial improvement in these properties (920 pC/N and 0.65, respectively) post-[001] texturing, attributed to the high R structure content (60%). Conversely, the untextured CP(Z0.34T0.66)-PNN ceramic, showing higher d33 (740 pC/N) and kp (0.63) values, experiences a reduction in these parameters to 480 pC/N and 0.52, respectively, after [001] texturing due to a lower content of the R structure (21%). Consequently, the study suggests that piezoceramics with a higher content of the R structure are more favorable for enhancing piezoelectric properties through [001] texturing.