铌酸钾钠无铅压电微纳单晶的可控制备与原位压电性能研究

High performance environmentally friendly lead-free piezoelectric materials have become a research of interest, and potassium sodium niobate ((K,Na)NbO3, abbreviated as KNN) is a representative material system. Additionally, significant progress has been made in the research of KNN ceramics. The piezoelectric micro/nano-single crystals have a good application prospect in the field of sensors, actuators and some other systems at the nanoscale. As a result, the lead-free piezoelectric micro/nano-single crystals have attracted more and more attention in recent years. Whereas, the studies of KNN micro/nano-single crystals are still in the initial phase, most of which focus on the preparation process. The current proposal considers KNN micro/nano-single crystals as the research object. The first aim is to controllably fabricate one dimensional and two dimensional KNN structures. Then, Piezoresponse Force Microscopy will play an important role in characterizing the piezoresponse and domain structures of micro/nano-single crystals. Finally, the relationship of piezoelectric response between micro/nano-single crystals and macro-ceramics will be established based on the experimental results. It is expected that the current project has important scientific significance, which will improve the theoretical research of KNN system, and provide a reference for other lead-free piezoelectric systems.

高性能环境友好型无铅压电材料已成为研究热点，其中铌酸钾钠（(K,Na)NbO3，简写为KNN）是一个具有代表性的材料体系，其块体陶瓷材料的研究取得了显著进展。由于微纳压电单晶材料在微纳传感器和驱动器等微系统中具有重要应用，近年来，无铅压电KNN微纳单晶的相关研究开始备受关注，但是研究处于起步阶段，主要侧重于制备工艺的探索。本课题以KNN微纳单晶材料为研究对象，首先，实现KNN一维、二维微纳单晶的可控制备，掌握其生长机理；然后，利用压电力显微镜对其原位压电响应与畴结构等进行测试；最后，建立KNN体系中微纳单晶与宏观陶瓷压电性能的关联。本课题的实施将补充和完善KNN体系的理论研究，并为其他无铅压电体系的研究提供借鉴，具有重要的科学意义。

由于微纳压电单晶材料在微纳传感器和驱动器等微系统中具有重要应用，近年来，环境友好型的无铅压电(K,Na)NbO3（KNN）体系的微纳单晶的相关研究备受关注。本项目以KNN低维微纳结构为研究对象，开展了该产物的可控制备及原位压电响应性能研究。申请人及团队围绕项目计划书中的三个研究内容，开展了一系列的研究，基本实现了研究目标：（1）辨析了KNN微纳单晶制备过程的影响因素及其生长规律，掌握了合成均匀目标产物的方法。明确了调控产物形貌和结构的主次因素及关键点；（2）实现了微观尺度下材料原位压电响应等的观测。利用压电力显微镜对产物表征，产物微观结构和压电性能都均匀一致。压电位移曲线体现了其压电特性；（3）理解了KNN微纳单晶压电响应与宏观陶瓷块体等之间的联系。通过对不同晶粒尺寸压电块体材料、压电复合物块体进行制备，以及压电材料在锂离子电池应用中的初步探索，明确了这种微纳结构具有巨大的应用潜力。于Dalton Transactions和RSC Advances等期刊发表论文9篇，申请发明专利1项。