FRG: Domain Orientation and Anisotropy in Poled Piezoelectrics

非技术描述压电材料对于传感器和致动器的应用至关重要，这些传感器和致动器能够实现医疗超声、促进骨骼愈合的治疗、高效便携式电力变压器、高性能柴油发动机以及涉及电能和机械能之间转换的许多其他应用。 该研究团队的目标是通过充分优化现有材料，提高我们对压电材料的理解，并增强环保无铅压电材料的工业发展潜力。 该研究项目还将针对从中学到大学开始的学生开发压电科学和工程方面的教材。 这些教材将用于加强数学和科学方面的技能发展，并培养对科学和工程的兴趣。技术规格：在极化，无铅压电晶体的晶畴取向和各向异性的纹理探索，使纹理和微观结构之间的相互关系的理解，可以导致更换含铅压电。本计画将结合块体材料中的畴结构与晶体结构，以了解压电及其他各向异性性质的发展。 极化场、极化温度、电导率和材料固有特性（如电导率和热导率、弹性和热膨胀）的影响是发展这种理解的关键方面。该项目包括开发生产散装材料的加工方法，这些材料可用于充分描述快速发展的无铅压电材料类别中纹理和各向异性之间的相互作用。 项目研究人员正在考虑通过扫描表面探针技术，作为应力状态、温度和加工历史的函数，在晶界上铁弹和铁电畴之间的纳米级和微米级相互作用。 实验方面是关键，以描述的纹理和微观结构的性能的关系进行比较，以深刻的微观结构为基础的数值模拟，捕获的热力学和物理发生的域和晶粒的规模。该项目的实验和计算方面将与汽车和柴油发动机行业以及达姆施塔特技术大学的同事合作进行。 该项目正在产生一个更好的理解极化过程中，施加在极化的铁电和铁电畴及其与晶界和微观结构的相互作用的基础上的限制。本科生和研究生研究人员正在学习先进的技术，用于数值模拟纳米尺度和微观尺度对性能的影响，表面探针分析和电子显微镜的样品制备技术，表面探针技术，电子显微镜和X射线和中子衍射技术。

NON-TECHNICAL DESCRIPTION Piezoelectric materials are critical for applications in sensors and actuators that enable medical ultrasound, therapies that promote bone healing, highly efficient portable power transformers, high performance diesel engines and many other applications involving conversion between electrical and mechanical energy. The goal of this research team is to improve our understanding of piezoelectrics by fully optimizing existing materials and enabling enhanced potential for industrial development of environmentally friendly, lead free piezoelectrics. The research project will also be directed towards developing educational materials on the science and engineering of piezoelectrics for students from middle school to beginning college. The educational materials will be used to enhance skill development in math and science and to foster interest in science and engineering. TECHNICAL DETAILS: Exploration of crystallographic texture with domain orientation and anisotropy in poled, lead free piezoelectrics enables understanding of the interrelationships between texture and microstructure that can lead to replacement of lead-containing piezoelectrics. This project will couple domain textures and crystallographic textures in bulk materials to understand the development of piezoelectric and other anisotropic properties. Effects of poling field, poling temperature, conductivity and intrinsic materials properties such as electrical and thermal conductivity, elasticity and thermal expansion are critical aspects for developing this understanding. The project consists of development of processing approaches to produce bulk materials that can be used to fully describe the interplay between texture and anisotropy in the rapidly evolving classes of lead free piezoelectric materials. Project investigators are considering nanoscale and microscale interactions between ferroelastic and ferroelectric domains across grain boundaries as a function of stress state, temperature and processing history via scanned surface probe techniques. The experimental aspects are pivotal to describing the relationship of texture and microstructure to properties for comparison to incisive microstructure-based numerical simulations that capture the thermodynamics and physics occurring on the scale of the domains and grains. Both the experimental and computational aspects of this project will be carried out in collaboration with colleagues in the automobile and diesel engine industries and at the Technical University of Darmstadt. This project is producing a better understanding of poling processes, the limitations imposed on poling by the underlying ferroelastic and ferroelectric domains and their interactions with grain boundaries and microstructure. Undergraduate and graduate student researchers are learning advanced techniques for numerical simulation of nanoscale and microscale effects on properties, sample preparation techniques for surface probe analysis and electron microscopy, surface probe techniques, electron microscopy and x-ray and neutron diffraction techniques.