Tailoring interface functionality of complex oxide heterostructures - A neutron and x-ray study

复杂氧化物异质结构的界面功能定制——中子和 X 射线研究

• 批准号: 1608752
• 负责人: Xianglin Ke
• 金额: $ 33.3万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1608752&HistoricalAwards=false
• 关键词: Tailoring; interface; functionality; complex; oxide

Non-technical Abstract: Complex transition-metal oxide heterostructures represent an emerging and rapidly growing field with both significant scientific merits and potential applications in spintronics, catalysts, solar cells, etc. A plethora of novel physical phenomena can arise at the interface of dissimilar materials in oxide heterostructures that are not attainable in the bulk constituents. This project investigates such novel phenomena in transition-metal oxide heterostructures via creation and manipulation of novel interface functionalities by tuning the substrate geometry and surface orientation. Importantly, this project serves as a platform to train the next-generation neutron and synchrotron x-ray scattering scientists, helping to promote the user community of the cutting-edge facilities in national laboratories. In addition to training graduate and undergraduate students, this project also supports the scientific research activities engaging high school teachers and K-12 students, as well as the activities of developing and presenting workshops to students in community colleges in Michigan. Technical Abstract: The project investigates the emergent quantum phenomena in correlated transition-metal oxide heterostructures via creation and manipulation of novel interface functionalities. Tuning the substrate geometry and surface orientation gives rise to diverse polar surface terminations, bond connections, and octahedral distortions, which are anticipated to affect electronic and orbital reconstruction as well as magnetic and structural coupling at the interfaces. Consequently, this can drastically alter physical properties of oxide heterostructures grown atop, providing a pathway to new physics and materials research. This project utilizes two unique and complementary techniques, i.e., polarized neutron reflectometry and polarized x-ray absorption spectroscopy, which offer high depth resolution and characteristic fingerprint of transition-metal elements to decisively determine the nature of interfacial magnetic and electronic states.

摘要：复杂过渡金属氧化物异质结构是一个新兴且快速发展的领域，在自旋电子学、催化剂、太阳能电池等方面具有重要的科学价值和潜在的应用前景。在氧化物异质结构中，在不同材料的界面上可能出现大量新的物理现象，而这些现象在主体成分中是无法实现的。本项目通过调整衬底几何形状和表面取向来创造和操纵新的界面功能，研究过渡金属氧化物异质结构中的这种新现象。重要的是，该项目作为培训下一代中子和同步加速器x射线散射科学家的平台，有助于促进国家实验室尖端设施的用户群体。除了培训研究生和本科生外，该项目还支持高中教师和K-12学生的科研活动，以及密歇根州社区学院学生的开发和演讲活动。技术摘要：该项目通过创建和操纵新的界面功能来研究相关过渡金属氧化物异质结构中的新兴量子现象。调整衬底的几何形状和表面方向会产生不同的极性表面终止、键连接和八面体畸变，这将影响界面上的电子和轨道重建以及磁和结构耦合。因此，这可以极大地改变生长在顶部的氧化物异质结构的物理性质，为新的物理和材料研究提供了途径。本项目利用极化中子反射法和极化x射线吸收光谱两种独特互补的技术，提供高深度分辨率和过渡金属元素特征指纹，决定性地确定界面磁态和电子态的性质。