The structural origin of enhanced piezoelectric performance and stability in lead free ceramics
The structural origin of enhanced piezoelectric performance and stability in lead free ceramics
复制标题
DOI：
10.1039/c6ee03597c
复制
发表时间：
2017-02
影响因子：
32.5
通讯作者：
Ting Zheng;Haijun Wu;Yuan Yuan-Yuan;X. Lv;Qi Li;Tian-Lu Men;Chunlin Zhao;D. Xiao;Jiagang Wu
中科院分区：
文献类型：
--
作者：
Ting Zheng;Haijun Wu;Yuan Yuan-Yuan;X. Lv;Qi Li;Tian-Lu Men;Chunlin Zhao;D. Xiao;Jiagang Wu
铅基压电材料由于其铅毒性，目前正面临全球限制。因此，开发具有高压电性和温度稳定性的无铅替代品是当务之急，其中铌酸钾钠[（K，Na）NbO 3，KNN]最具潜力。在基于KNN的系统中同时实现高压电性能和可靠的稳定性是非常困难的。特别是，其高压电性的结构/物理起源仍然不清楚，这阻碍了性能优化。在这里，我们报告的成就，高温稳定性（27 °C至80 °C的电场诱导应变变化小于10%），良好的疲劳性能（稳定达106次循环）以及525 pC N−1 in（1 − x）（K1−yNay）的增强压电系数（d33）（Nb 1 −zSbz）O3-xBi0.5（Na 1 −wKw）0.5HfO3（KNNS-BNKH）陶瓷。其高压电性能的结构起源可归因于分层纳米畴结构，其中纳米畴内的局部结构包括R和T纳米双晶。其物理原因可以归结为较低的畴壁能和几乎消失的极化各向异性，使得不同态之间容易发生极化旋转。我们相信，这一新的突破将为KNN基陶瓷的实际应用打开一扇窗户。
Lead-based piezoelectric materials are currently facing global restrictions due to their lead toxicity. Thus it is urgent to develop lead-free substitutes with high piezoelectricity and temperature stability, among which, potassium-sodium niobate [(K,Na)NbO3, KNN] has the most potential. It is very difficult to simultaneously achieve high piezoelectric performance and reliable stability in KNN-based systems. In particular, the structural/physical origin for their high piezoelectricity is still unclear, which hinders property optimization. Here we report the achievement of high temperature stability (less than 10% variation for electric field-induced strain from 27 °C to 80 °C), good fatigue properties (stable up to 106 cycles) as well as an enhanced piezoelectric coefficient (d33) of 525 pC N−1 in (1 − x)(K1−yNay)(Nb1−zSbz)O3–xBi0.5(Na1−wKw)0.5HfO3 (KNNS–BNKH) ceramics through manipulating the rhombohedral–tetragonal (R–T) phase boundary. The structural origin of their high piezoelectric performance can be attributed to a hierarchical nanodomain architecture, where the local structure inside nanodomains comprises R and T nanotwins. The physical origin can be attributed to low domain wall energy and nearly vanishing polarization anisotropy, facilitating easy polarization rotation among different states. We believe that the new breakthrough will open a window for the practical applications of KNN-based ceramics.