Texture-controlled electrostain response in PNN-PZT multilayer piezoelectric ceramic actuators enabled by asymmetric stacking strategy

Multilayer piezoelectric textured ceramic actuators (T-MLCAs) of 0.5Pb(Ni_1/3Nb_2/3)O₃-0.16PbZrO₃-0.34PbTiO₃ (PNNZT) fabricated by two-dimensionally-dispersed template grain growth (2DD-TGG) are introduced. The texture morphology and electrostrain properties of the PNNZT T-MLCA by 2DD-TGG, co-fired at 1000°C for 48 h, were comparatively investigated by varying the stacking order of the sheets forming the MLCA. The PNNZT T-MLCA by 2DD-TGG with the asymmetrical stacking order in the vertical direction showed outstanding textured grain morphology, compared with the symmetrical counterpart. This is because heat supplied by the electrode during sintering contributes to the growth of the PNNZT textured grains. An extremely large d₃₃* value of 1182 pm/V at 0.5 kV/mm was achieved for the PNNZT T-MLCA by 2DD-TGG with the asymmetrical stacking order. In addition, its d₃₃* value was degraded as low as approximately 4.4 % up to 10⁶ unipolar cycles, indicating that the actuator has excellent long lifetime.