Coherent Precipitates with Strong Domain Wall Pinning in Alkaline Niobate Ferroelectrics
Coherent Precipitates with Strong Domain Wall Pinning in Alkaline Niobate Ferroelectrics
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DOI：
10.1002/adma.202202379
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发表时间：
2022-08
影响因子：
29.4
通讯作者：
Changhao Zhao;Shuang Gao;H. Kleebe;X. Tan;J. Koruza;J. Rödel
中科院分区：
文献类型：
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作者：
Changhao Zhao;Shuang Gao;H. Kleebe;X. Tan;J. Koruza;J. Rödel
预计到2024年，高功率压电应用将占无铅压电陶瓷市场的约三分之一，碱性铌酸盐将成为主要竞争对手。为了抑制大功率器件在大电场驱动下由于机械损耗而产生的自热，需要采用压电硬化来限制畴壁运动。在目前的工作中，在（Li,Na）NbO3 （LNN）固溶体模型系统中，通过相干板状析出物进行的高效压电硬化可以减少损耗，并将损耗量化为机电质量因子，减少了十倍。不同的热时效方案可以控制析出相的平均尺寸、数量密度和位置。所建立的性质分别与X射线衍射和对分布函数分析的短程和远程原子结构的详细测定以及透射电子显微镜的微观结构有关。还确定了带有析出相的微观结构对小场和大场性能的影响。这些结果为在压电材料中实现沉淀硬化铺平了道路，类似于金属中的沉淀硬化，扩大了它们在应用中的使用案例。
High‐power piezoelectric applications are predicted to share approximately one‐third of the lead‐free piezoelectric ceramic market in 2024 with alkaline niobates as the primary competitor. To suppress self‐heating in high‐power devices due to mechanical loss when driven by large electric fields, piezoelectric hardening to restrict domain wall motion is required. In the present work, highly effective piezoelectric hardening via coherent plate‐like precipitates in a model system of the (Li,Na)NbO3 (LNN) solid solution delivers a reduction in losses, quantified as an electromechanical quality factor, by a factor of ten. Various thermal aging schemes are demonstrated to control the average size, number density, and location of the precipitates. The established properties are correlated with a detailed determination of short‐ and long‐range atomic structure by X‐ray diffraction and pair distribution function analysis, respectively, as well as microstructure determined by transmission electron microscopy. The impact of microstructure with precipitates on both small‐ and large‐field properties is also established. These results pave the way to implement precipitate hardening in piezoelectric materials, analogous to precipitate hardening in metals, broadening their use cases in applications.