Materials World Network: Experimental Observation and Theoretical Modeling of Domain Evolution in Ferroelectrics

材料世界网络：铁电体域演化的实验观察和理论建模

• 批准号: 0909139
• 负责人: Chad Landis
• 金额: $ 25万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909139&HistoricalAwards=false
• 关键词: Materials; World; Network; Experimental; Observation

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Ferroelectric ceramics have unique properties, including piezoelectricity, pyroelectricity, the electro-optic effect, phase change, and polarization switching. These special properties make them useful for a wide range of technological applications. For example, medical ultrasound scanners, random access memories, infrared camera sensors, electro-optic modulators, sonar beacons, vibration controllers, and diesel engine fuel injectors all make use of ferroelectric materials. The proposed research program will advance the field of experimental and theoretical characterization of the behavior of ferroelectric materials. Experimental and theoretical methods developed in this program will be applicable to the study of other "smart" materials including shape memory alloys and ferromagnetic shape memory alloys. Through this research, doctoral students will be trained in a collaborative project with international activity: students will train at University of Texas, Austin, and University of Oxford (UK). To broaden participation from underrepresented groups the principal investigators will continue their track record of leveraging institutional resources to recruit women and minority students. The research will ultimately benefit society by developing a fundamental understanding of the behavior ferroelectric materials, which will support and stimulate the design of novel ferroelectric devices for numerous and diverse technological applications.The merit of this Materials World Network international collaborative research program originates from the joint application of state of the art experimental characterization (in the UK) and theoretical modeling (in the US) of domain structure nucleation, growth and evolution in single crystal ferroelectric ceramics. To date there have been several outstanding experimental and theoretical studies on ferroelectric crystals, but none of these studies has systematically integrated experimental observations that can critically test model predictions with a modeling framework that is, in turn, able to suggest innovative experimental studies. The experimental component of the research uses atomic and piezo-force microscopy, X-ray sychrotron, and birefringence methods to directly observe ferroelectric domain structure evolution under thermal, electrical and mechanical loadings. Each experimental configuration is also studied and interpreted through the lens of detailed numerical solutions of the Landau-Ginsburg-Devonshire phase-field equations. The studies focus on two categories: (1) evolution of existing structures including isolated domain walls subjected to static and alternating fields, and the evolution of domain needles and domain vortices, and (2) the nucleation of domain structures due to cooling through the Curie temperature, and from field concentrators like electrode tips and material inclusions. During the course of the research, two doctoral students will be trained in a strongly collaborative project with international activity. Each student will spend six months in the counterpart institution, with these exchanges timed to allow the research students to work together and thus gain expertise in both theoretical and experimental methods. The detailed experimental characterization and predictive modeling of domain structure evolution from this research will support and stimulate the design of the next generation of novel ferroelectric devices.

该奖项是根据 2009 年美国复苏和再投资法案（公法 111-5）资助的。铁电陶瓷具有独特的性能，包括压电性、热电性、电光效应、相变和偏振切换。这些特殊性能使其可用于广泛的技术应用。例如，医用超声波扫描仪、随机存取存储器、红外相机传感器、电光调制器、声纳信标、振动控制器和柴油发动机燃油喷射器都使用铁电材料。拟议的研究计划将推进铁电材料行为的实验和理论表征领域。该项目开发的实验和理论方法将适用于其他“智能”材料的研究，包括形状记忆合金和铁磁形状记忆合金。通过这项研究，博士生将在一个具有国际活动的合作项目中接受培训：学生将在德克萨斯大学奥斯汀分校和牛津大学（英国）接受培训。为了扩大代表性不足群体的参与，主要研究人员将继续利用机构资源招收女性和少数族裔学生。该研究最终将通过对铁电材料行为的基本了解而造福社会，这将支持和刺激用于众多不同技术应用的新型铁电器件的设计。该材料世界网络国际合作研究计划的优点源于联合应用最先进的实验表征（在英国）和理论建模（在美国）单晶铁电陶瓷中的域结构成核、生长和演化。 迄今为止，已经有一些关于铁电晶体的杰出实验和理论研究，但这些研究都没有系统地整合实验观察，从而可以用建模框架批判性地测试模型预测，从而能够提出创新的实验研究。 该研究的实验部分使用原子和压力显微镜、X射线同步加速器和双折射方法来直接观察热、电和机械负载下的铁电畴结构演化。 每个实验配置还通过兰道-金斯伯格-德文郡相场方程的详细数值解的镜头进行了研究和解释。 研究重点关注两类：（1）现有结构的演变，包括受到静态和交变场作用的孤立畴壁，以及畴针和畴涡的演变，以及（2）由于居里冷却而导致的畴结构的成核温度，以及来自场集中器（如电极尖端和材料夹杂物）的影响。 在研究过程中，两名博士生将在一个具有国际活动的强有力的合作项目中接受培训。 每个学生将在对应机构度过六个月的时间，这些交流的时间安排是为了让研究生能够一起工作，从而获得理论和实验方法方面的专业知识。 这项研究的域结构演化的详细实验表征和预测建模将支持和刺激下一代新型铁电器件的设计。