基于极化协同机制的高性能无铅压电陶瓷制备及性能调控研究

It’s limited to improve the piezoelectric properties of lead-free ceramics by following the research thoughts of the conventional composition driven ferroelectric-ferroelectric phase transition. It’s in need to explore new method and mechanism to guide the research and development of the high-performance lead-free piezoelectric materials. In this project, the BiFeO3 based lead-free piezoelectric ceramics are selected as the research object. The intrinsic constitutive relations and laws between the phase transition/polarization and properties of the lead-free piezoelectric ceramics will be explored. The principle of the composition driven ferroelectric-ferroelectric/non-ferroelectric phase transition and polarization rotation and extension cooperation mechanism will be studies deeply. The theoretical model of the ferroelectric-ferroelectric/non-ferroelectric phase transition and polarization will be established. The phase diagram and structure/property control mechanism of the BiFeO3 based lead-free piezoelectric ceramics will be obtained. It’s expected to break through the limitations of the conventional lead-free piezoelectric materials and get the practical lead-free piezoelectric ceramics with high quality, high performance and high Curie temperature. This project will provide new academic ideas for the design and preparation of lead-free piezoelectric materials, achieve the innovation of lead-free piezoelectric material system and theoretical mechanism, and promote the development and application of lead-free piezoelectric materials.

采用传统的组分驱动铁电-铁电相变的研究思路提升无铅陶瓷压电性能的空间十分有限，急需探索新方法和新机制指导高性能无铅压电材料的研究和开发。本项目以铁酸铋基无铅压电陶瓷为研究对象，探索无铅压电陶瓷性能与相变/极化的内在本质关系和规律，深入研究组分驱动的铁电-铁电/非铁电相变原理和极化偏转-扩展协同机制，建立组分驱动的铁电-铁电/非铁电相变和极化理论模型，获得铁酸铋系列无铅压电陶瓷的相图和结构/性能调控机制，有望突破传统无铅压电材料的瓶颈，获得高质量、高性能、高居里温度的实用型无铅压电陶瓷。本项研究为无铅压电材料的设计与制备提供新学术思想，实现无铅压电材料体系和理论机制的创新，促进无铅压电材料的发展与应用。

压电材料是实现机械能与电能相互转换的一类重要功能材料，在传感器、驱动器、超声换能器、谐振器、滤波器等各种电子器件方面有着广泛的应用。目前，在电子器件中应用的压电材料主要是铅基压电陶瓷。研究和开发环境协调性的高性能无铅压电陶瓷是目前压电材料领域的发展趋势和研究重点。本项目采用溶胶-凝胶法结合新型陶瓷制备工艺制备了铁酸铋基无铅压电纳米粉体和陶瓷，研究了铁酸铋基无铅压电陶瓷微结构和电学性能，发现了工艺参数、掺杂元素及组分等因素与陶瓷结构相变、相稳定性、极化特性和介电、铁电、压电性能之间的关系和规律；研究了温度和组分调控对铁酸铋基无铅压电陶瓷相变结构和稳定性的影响。最终获得具有高质量（相对密度 > 95%）、高压电性能 (d33 > 400 pm/V)、高居里温度 (TC > 400oC) 的新型铁酸铋基无铅压电陶瓷。