Low-temperature co-fired PZNN-PZT multilayer piezoelectric ceramics with excellent electrical and bending properties

A 0.65 Pb(Zr0.47Ti0.53)O3-0.35[Pb(Zn0.1Ni0.9)1/3Nb2/3]O3 (PZNN-PZT) piezoceramic with sintering aids of Li2CO3, Bi2O3, CuO and Sm2O3 was prepared via a traditional solid reaction to achieve a high-performance multilayer actuator. The microstructure and electrical properties of ceramic bulks were systematically explored. The piezoceramics sintered at various temperatures show multi-phase co-existence. The sintering aids are beneficial for grain growth and microstructure densification. The piezoceramic sintered at 960 degrees C possesses relatively desirable electrical properties, including d33 -550 pC/N, kp-0.7 epsilon r-2200, tan delta-0.021, Qm-71, Tc-240.5 degrees C, Pr-24.44 mu C/cm2 and Ec-823.7 V/cm. Furthermore, we employed the tape casting and low-temperature co-fire methods to fabricate a PZT-PZNN/Ag-Pd multilayer piezoceramic of 7 x 7 x 36 mm3 in dimension with a single ceramic film of about 80 mu m in thickness. The Ag-Pd electrode is effectively bonded with the ceramic layer, especially chemical binding induced by oxygen diffusion at some partial areas, which plays a crucial role in high binding strength (-9.2 MPa). The multilayer piezoceramic exhibits outstanding actuating characteristics of high Smax-55.53 mu m @ 150 V, and low H-19.8% @ 150 V together with outstanding stiffness of 70.87 N/mu m @ 150 V.