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

Abstract

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 °C possesses relatively desirable electrical properties, including d33 ∼ 550 pC/N, kp ∼0.7 εr ∼2200, tan δ ∼0.021, Qm ∼71, Tc ∼240.5 °C, Pr ∼24.44 μC/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 × 7 × 36 mm3 in dimension with a single ceramic film of about 80 μm 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 μm @ 150 V, and low H ∼19.8% @ 150 V together with outstanding stiffness of 70.87 N/μm @ 150 V.