CAREER: Enhanced Pyroelectric and Electrocaloric Effects in Complex Oxide Thin Film Heterostructures

职业：复合氧化物薄膜异质结构中增强的热电和电热效应

• 批准号: 1149062
• 负责人: Lane Martin
• 金额: $ 55万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1149062&HistoricalAwards=false
• 关键词: CAREER; Enhanced; Pyroelectric; Electrocaloric; Effects

NON-TECHNICAL DESCRIPTION: Advances in the development of functional complex oxide materials have enabled many of the devices that are utilized on a daily basis from memories to actuators and beyond. This project is developing a deeper understanding of electro-thermal responses of materials and finding routes to enhance those effects to enable advanced thermal imaging (e.g., night-vision systems), waste-heat energy conversion for energy efficiency, novel electron emission for high-tech applications, and low-power solid-state cooling for nanoelectronics. This project is developing a design algorithm by which researchers can enhance the electric-field and temperature-dependent response of materials for such applications. Possible applications range from communications to data storage to logic to sensing devices. Fundamental research in these fields fosters the United States innovation in the growing green economy and high-technology spaces. The project includes research on the creation of new and complex materials, computational and theoretical approaches to materials design and optimization, and advanced characterization of materials properties. The project also promotes discovery and understanding at the K-12/undergraduate/graduate education levels by introducing students to advanced functional materials and broadening the participation (through personal interaction and recruitment) of underrepresented student groups in science and engineering careers.TECHNICAL DETAILS: This project provides the one of the first studies of so-called magneto-electro-caloric and pyro-electric-magnetic effects, which make use of coupled order parameters in multiferroic/magneto-electrics. Additionally, the project is investigating frustrated ferroelectric order which should provide for large entropic changes with applied fields. The research project combines advances in phenomenological models, cutting-edge thin-film growth techniques (including pulsed-laser deposition and molecular beam epitaxy), and modern characterization techniques to develop a deeper understanding of the physics and thermodynamics of thermo-electrical responses (i.e., pyroelectric and electrocaloric effects) in complex oxide materials. This project is providing new insight into the underlying mechanisms of such thermo-electrical responses and seeking pathways to manipulate and control the temperature- and field-dependence of entropic changes in ferroic oxides. The overall goal of the project is to further the fundamental understanding of these effects, to develop predictive capabilities for responses in thin-film systems, and to probe the properties and ultimate performance of these materials to enable their use in devices. As part of this project, the researchers are creating and characterizing high-quality, heteroepitaxial, thin-film heterostructures and nanostructures of complex oxide materials and in turn, are investigating innovative approaches to enhance thermo-electrical responses in materials by exploring the temperature- and field-dependence of entropy in modern materials. The project is also providing fundamental insight into the physics of these effects by developing novel Ginzburg-Landau-Devonshire models of these thermodynamic properties that include effects from domain walls, polydomain structures, layered heterostructures, strain and composition gradients, and other features common in films. Finally, the project seeks to identify and overcome inadequacies in characterization of such properties, including the utilization of new techniques to provide the first direct measurement of such effects in thin films.

非技术描述：功能复杂氧化物材料的发展的进步已使许多设备每天都从记忆到执行器及其他设备。该项目正在对材料的电热反应有了更深入的了解，并找到了增强这些效果的途径，以实现高级热成像（例如，夜间视觉系统），用于能源效率的废热能量转换，高型技术应用的新型电子排放以及用于纳米电子的低功耗固态固态。该项目正在开发一种设计算法，研究人员可以通过该算法来增强用于此类应用的材料的电场和温度依赖性响应。可能的应用程序从通信到数据存储到逻辑到传感设备。这些领域的基本研究促进了美国日益增长的绿色经济和高科技空间的创新。该项目包括有关创建新和复杂材料的研究，材料设计和优化的计算和理论方法，以及材料属性的高级表征。该项目还通过向学生介绍先进的功能材料并扩大了代表性不足的科学和工程职业的参与（通过个人互动和招聘）来促进K-12/本科/研究生教育水平的发现和理解。技术详细信息：该项目提供了最早的磁磁效果研究的一项，该项目构成了一种效果的一项研究，该项目是对磁性效果的效果。多效/磁电极中的耦合顺序参数。此外，该项目正在调查沮丧的铁电顺序，该秩序应为应用领域提供大规模的熵变化。该研究项目结合了现象学模型，最先进的薄膜增长技术（包括脉冲激光沉积和分子束外延）以及现代表征技术，以更深入地了解对热电机反应的热力学和热力学的现代特征技术（即，Pyroelectric and Electocecoaloric oxide材料）。该项目正在提供有关此类热电反应的潜在机制的新见解，并寻求操纵和控制铁族氧化物熵变化的温度和田间依赖性的途径。该项目的总体目标是进一步了解这些影响，以开发薄膜系统中响应的预测能力，并探究这些材料的性能和最终性能，以便在设备中使用它们。作为该项目的一部分，研究人员正在创建和表征复杂氧化物材料的高质量，杂质，薄膜异质结构和纳米结构，进而研究创新的方法，以通过探索现代材料中的入口处的温度和现场依赖性，从而增强材料中的热电响应。该项目还通过开发这些热力学特性的新颖的金兹堡 - 兰道象模型来提供对这些作用物理学的基本见解，其中包括来自域壁，多域结构，多域结构，分层异质结构，应变和组成梯度以及电影中常见的其他特征的作用。最后，该项目旨在识别和克服这种特性表征的不足，包括利用新技术来首次直接测量薄膜中此类效应。