Phase structure and enhanced piezoelectric properties in (1-x)(K_0.48Na_0.52)(Nb_0.95Sb_0.05)O₃-x(Bi_0.5Na_0.42Li_0.08)_0.9Sr_0.1ZrO₃ lead-free piezoelectric ceramics

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• 作者：Laiming Jiang ; Yueyi Li ; Jie Xing ; Jiagang Wu ; Qiang Chen ; Hong Liu ; ^{liuh@scu.edu.cn} ; Dingquan Xiao ; Jianguo Zhu ; ^{nic0400@scu.edu.cn}
• 关键词：KNN ceramics ; Phase structure ; R-T phase boundary ; Large piezoelectricity
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：43
• 期：2
• 页码：2100-2106
• 全文大小：1418 K
• 卷排序：43

文摘

The piezoelectric properties of KNN lead-free piezoelectric ceramics could be greatly enhanced by forming multiphase coexistence. In this work, binary system (1-x)(K0.48Na0.52)(Nb0.95Sb0.05)O3-x(Bi0.5Na0.42Li0.08)0.9Sr0.1ZrO3 [(abbreviated as (1-x)KNNS-xBNLSZ] ceramics with rhombohedral-tetragonal (r-T) phase boundary was designed and synthesized using the conventional solid-state sintering method, and effects of BNLSZ contents on their micrograph, phase structure and electrical properties were also investigated. According to phase diagram from the results of temperature-dependent capacitance and dielectric constant, the ceramics exhibit the R-T phase coexistence in the composition range of 3.5%≤x<4.5%, and an enhanced dielectric, ferroelectric, and piezoelectric behavior was obtained at such a phase boundary zone. As a result, the ceramics with x=0.04 exhibit optimum electrical properties of d33~461 pC/N, kp~46%, tan δ~0.03, Pr~16.9 μC/cm2, and Ec ~9 kV/cm, together with a Curie temperature (TC) of ~228 °C. Such a good comprehensive performance obtained in this present work is due to the R-T phase transition and enhanced ɛrPr. It was believed that this ceramic system would promote the development of KNN-based lead-free ceramics.