Fabrication, temperature stability and characteristics of Pb(ZrxTiy)O3–Pb(Zn1/3Nb2/3)O3–Pb(Ni1/3Nb2/3)O3 piezoelectric ceramics bimorph

The phase structure, microstructure, electrical properties and the temperature stabilities of Pb(ZrxTiy)O3–Pb(Zn1/3Nb2/3)O3–Pb(Ni1/3Nb2/3)O3 (PZT–PZN–PNN) ceramics are investigated in order to identify the morphotropic phase boundary composition in this system. The pure perovskite structure could be confirmed in all ceramics. The ceramics obtains the optimal piezoelectric properties at Zr/Ti ratio = 0.985, which are listed as follows: d33 = 552 pC/N, Kp = 0.77, Qm = 70, tan δ = 0.0150 and ɛr = 2659. When Zr/Ti ratio is 0.985, the values of Δfr/fr25 °C and ΔKp/Kp25 °C curves fluctuate around the zero, which indicate that the favorable temperature stability are obtained. Meanwhile, piezoelectric ceramics bimorph using PZT–PZN–PNN ceramics with Zr/Ti ratio of 0.985 is fabricated successfully by the tape-casting technology. The piezoelectric ceramics bimorph sintered at 1000 °C exhibits a larger displacement of 1683 μm at the working voltage of 180 V. The results indicate that the piezoelectric ceramics bimorph meets the needs of the needle selecting mechanism of electronic jacquard.