CAREER: Multifunctional Heterostructures of Perovskite Structured Materials

职业：钙钛矿结构材料的多功能异质结构

• 批准号: 0747896
• 负责人: Yayoi Takamura
• 金额: $ 40万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0747896&HistoricalAwards=false
• 关键词: CAREER; Multifunctional; Heterostructures; Perovskite; Structured

NON-TECHNICAL DESCRIPTION: The development of next generation spintronic devices, sensors, and low temperature solid oxide fuel cells requires the development of materials with new functional properties not found in conventional bulk materials. A novel route involves harnessing the unexpected physical phenomena that result from the changes in structure and chemistry which occur over nanometer scales at surfaces and interfaces. The approach of this work utilizes laser-assisted growth to control interfacial properties with atomic layer precision in combination with state-of-the-art techniques for characterizing the structural and chemical properties. In this way, a full understanding of the origins of new magnetic and electronic properties derived from interfacial mechanisms can be determined. The research activities involve training of undergraduate and graduate researchers, including under-represented minorities through the NSF California Alliance for Minority Participation (CAMP) program. Furthermore, a Science, Technology, Engineering, and Mathematics (STEM) workshop brings educationally disadvantaged students from community colleges around Northern California to UC Davis to experience first hand what the science and engineering programs at UC Davis can offer them. TECHNICAL DESCRIPTION: The objective of this CAREER proposal involves understanding and harnessing surface and interfacial phenomena in artificial heterostructures and nanocomposites which possess multiple functional properties as needed for next generation spintronic devices, sensors, and low temperature solid oxide fuel cells. Perovskite structured materials are chosen as the platform for this work for their diverse and tunable functional properties. The unique aspect of this work involves the combined expertise in two equally important areas. First, heterostructures and nanocomposites with precisely controlled chemical and structural parameters are grown by pulsed laser deposition. Nanocomposites consisting of isolated islands embedded in a matrix are defined by a structural modification through a two-step process of e-beam lithography followed by ion implantation. Second, sophisticated characterization techniques are used to carefully probe both the local surface and interfacial properties and their effect on the overall global functional properties. In particular, synchrotron radiation based techniques which offer surface sensitive and chemically selective information on the electronic structure and magnetic characteristics of each layer are employed. Together, these steps provide a means of gaining a fundamental understanding of surface and interfacial effects which can be harnessed towards the control of the multifunctionality of materials systems.

非技术描述：下一代自旋电子器件、传感器和低温固体氧化物燃料电池的发展需要开发具有传统大块材料中没有的新功能特性的材料。一种新的途径涉及利用意想不到的物理现象，这些现象是由表面和界面在纳米尺度上发生的结构和化学变化引起的。这项工作的方法利用激光辅助生长来控制原子层精度的界面性质，并结合最先进的技术来表征结构和化学性质。通过这种方式，可以确定从界面机制中获得的新磁性和电子性质的来源的充分理解。研究活动涉及对本科生和研究生研究人员的培训，包括通过国家科学基金会加州少数民族参与联盟（CAMP）计划培训未被充分代表的少数民族。此外，科学、技术、工程和数学（STEM）研讨会将来自北加州社区大学的教育弱势学生带到加州大学戴维斯分校，亲身体验加州大学戴维斯分校的科学和工程项目能为他们提供什么。技术描述：本职业计划书的目标包括理解和利用人工异质结构和纳米复合材料中的表面和界面现象，这些材料具有下一代自旋电子器件、传感器和低温固体氧化物燃料电池所需的多种功能特性。钙钛矿结构材料因其多样化和可调的功能特性而被选择作为这项工作的平台。这项工作的独特之处在于将两个同等重要的领域的专业知识结合起来。首先，利用脉冲激光沉积技术生长出具有精确控制化学和结构参数的异质结构和纳米复合材料。纳米复合材料由嵌入在基体中的孤岛组成，通过电子束光刻和离子注入两步工艺对结构进行修饰。其次，使用复杂的表征技术仔细地探测局部表面和界面性质及其对整体功能性质的影响。特别是，同步辐射技术，提供表面敏感和化学选择性信息的电子结构和磁特性的每一层被采用。总之，这些步骤提供了一种获得对表面和界面效应的基本理解的方法，可以用来控制材料系统的多功能。