铈掺杂PZN-PZT三元系压电陶瓷的烧结特性研究

Study on Sintering Characteristics of Ce-doped PZN-PZT Ternary Piezoelectric Ceramics

采用传统的固相反应法制备了掺杂0.2 wt.%CeO_(2)的0.3Pb(Zn_(1/3)Nb_(2/3))O3-0.7Pb(Zr_(0.52)Ti_(0.48))O3(0.3PZN-0.7PZT-0.2Ce)三元系压电陶瓷,并研究了烧结温度(1190~1260℃)对其相结构、微观形貌以及电学性能的影响。XRD和SEM分析发现:所有烧结样品均呈纯的钙钛矿相结构,随着烧结温度的升高,陶瓷样品的相结构从三方相逐渐转变为四方相,1230℃烧结得到的样品由三方相和四方相共存;当烧结温度高于1230℃过后,晶粒开始显著长大,直至液相始出现。介电温谱研究证实:随着烧结温度的升高,0.3PZN-0.7PZT-0.2Ce陶瓷的居里温度(Tc)逐渐升高而介电损耗因子(tanδ)逐渐降低,1230℃烧结得到的样品介电常数(ε_(r))最大而温度系数(TKε)最小。压电性能以及谐振-反谐振测试表明:提高烧结温度有助于提升陶瓷的压电性能(d_(33))和机电耦合性能(kp),但过高的烧结温度(1260℃)也会使得性能恶化。综合来看:1250℃烧结得到的样品电学性能最佳:Tc=293℃,d_(33)=515 pC/N,kp=67%,ε_(r)=2493,TKε(120℃)=6.22×10^(-3)/℃,tanδ=0.017。

The 0.3Pb(Zn_(1/3)Nb_(2/3))O3-0.7Pb(Zr_(0.52)Ti_(0.48))O3(0.3PZN-0.7PZT-0.2Ce)ternary piezoelectric ceramics doped with 0.2 wt.%CeO_(2)were prepared by the traditional solid-state reaction process.The effects of sintering temperature(1190~1260℃)on their phase structures,microstructural morphologies and electrical properties were studied.XRD and SEM analysis showed that all sintered samples showed pure perovskite phase structure.With the increase of sintering temperature,the phase structure of ceramic samples gradually changes from tripartite phase to tetragonal phase.Sintered at 1230℃,both tripartite phase and tetragonal phase coexisted in the prepared samples.When the sintering temperature exceeded 1230℃,grains begin to grow significantly until the liquid phase appeared.The study of dielectric temperature spectrum shows that with the increase of sintering temperature,the Curie temperature(TC)of 0.3PZN-0.7PZT-0.2Ce ceramics gradually increases while the dielectric loss factor(tanδ)gradually decreases.The sample sintered at 1230℃achieved the largest dielectric constant(ε_(r))and the lowest temperature coefficient(TKε).The measurements of piezoelectric properties and resonance-antiresonance show that the increase of sintering temperature is conducive to the improvement of the piezoelectric properties(d_(33))and electromechanical coupling properties(kp),but a too high sintering temperature(1260℃)also deteriorates the electrical properties.In general,the sample sintered at 1250℃achieved the best electrical properties including:TC=293℃,d_(33)=515 pC/N,kp=67%,ε_(r)=2493,TKε(120℃)=6.22×10^(-3)/℃,tanδ=0.017.