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开发需要开发具有传统块状材料所没有的新功能特性的材料。一种新颖的途径涉及利用表面和界面纳米尺度上发生的结构和化学变化所产生的意想不到的物理现象。这项工作的方法利用激光辅助生长以原子层精度控制界面特性，并结合最先进的技术来表征结构和化学特性。 通过这种方式，可以充分了解源自界面机制的新磁和电子特性的起源。研究活动包括通过 NSF 加州少数族裔参与联盟 (CAMP) 计划培训本科生和研究生研究人员，包括代表性不足的少数族裔。此外，科学、技术、工程和数学 (STEM) 研讨会将北加州各地社区学院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可以为他们提供什么。技术描述：本职业提案的目标涉及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且可调节的功能特性而被选为这项工作的平台。这项工作的独特之处在于结合了两个同等重要领域的专业知识。首先，通过脉冲激光沉积生长具有精确控制的化学和结构参数的异质结构和纳米复合材料。由嵌入基质中的孤立岛组成的纳米复合材料是通过电子束光刻和离子注入的两步过程进行结构修改来定义的。其次，使用复杂的表征技术来仔细探测局部表面和界面特性及其对整体全局功能特性的影响。特别地，采用基于同步加速器辐射的技术，该技术提供关于每层的电子结构和磁特性的表面敏感和化学选择性信息。总之，这些步骤提供了一种对表面和界面效应有基本了解的方法，可用于控制材料系统的多功能性。