权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Understanding Spin Diffusion Lengths in Metals and Oxides

了解金属和氧化物中的自旋扩散长度

基本信息

批准号：
1807124
负责人：
Christopher Leighton
金额：
$ 40.66万
依托单位：
University of Minnesota-Twin Cities
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2021-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1807124&HistoricalAwards=false
关键词：
Understanding Spin Diffusion Lengths Metals

项目摘要

Non-technical abstract:High performance magnetic devices are ubiquitous in our society, the magnetic hard disk drives that power cloud data storage serving as one example. Underpinning technological advancement in this area is the ongoing progress in fundamental understanding of magnetism and magnetic materials. In this project, a fundamental problem relevant to "spin electronics" is being tackled, specifically how electron spins relax after being pumped from magnetic to non-magnetic materials. This is a poorly understood issue in magnetism, despite many scientific efforts and high importance for next generation devices. In this work, a particular type of nanomagnetic device is being used to understand, quantitatively, and for the first time, how specific materials defects control the relaxation of spins. In addition to advancing basic scientific knowledge, broader impact is being achieved through societal benefits from device applications, through education of students, and through outreach to the public. The latter involves collaboration with the Science Museum of Minnesota, developing exhibits and performances on the science of materials in our everyday lives, thus raising awareness of the role of materials research in our society.Technical abstract:Central to many spintronic phenomena and devices is the flow of a pure spin current, or a spin-polarized charge current, in a non-magnetic metal. A fundamental question in such a situation is over what distance does a non-equilibrium spin population relax in a non-magnetic metal, or: what is the spin diffusion length? Remarkably, while the basic mechanism governing metallic spin relaxation, the Elliot-Yafet mechanism, is known, there remain massive gaps in our understanding of this process. The individual effects of specific defects remain unknown, preventing quantitative or predictive understanding of spin transport. Addressing this problem, with its obvious technological relevance, would constitute a transformative advance. The essence of this project is to use non-local lateral spin valves to determine spin diffusion lengths in a variety of conventional and oxide-based metals. Elemental metals such as Al are being studied to separately quantify spin relaxation due to phonons, impurities, grain boundaries, surfaces, and interfaces, thus determining Elliott-Yafet constants for each defect. Metallic perovskite oxides are also being studied. These materials offer tremendous potential for spintronics, although an understanding of their spin diffusion lengths remains elusive. A progression from conventional metal-based devices to perovskite metals is being followed in this research, providing the first understanding of spin diffusion lengths in oxide ferromagnets and non-magnetic metals, a critical step in the development of oxide spintronics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要：高性能的磁性设备在我们的社会中无处不在，为云数据存储提供动力的磁性硬盘驱动器就是一个例子。支撑这一领域技术进步的是对磁性和磁性材料的基本认识的持续进步。在这个项目中，一个与“自旋电子学”相关的基本问题正在被解决，特别是电子自旋在从磁性材料泵浦到非磁性材料后如何松弛。这是一个在磁学方面知之甚少的问题，尽管有许多科学努力，但对下一代设备非常重要。在这项工作中，一种特殊类型的纳米磁性设备被用来定量地理解，并首次了解特定的材料缺陷如何控制自旋的弛豫。除了促进基本的科学知识外，通过设备应用的社会效益、通过对学生的教育以及通过向公众宣传，正在产生更广泛的影响。后者涉及与明尼苏达州科学博物馆的合作，在我们的日常生活中开发关于材料科学的展览和表演，从而提高人们对材料研究在我们社会中作用的认识。技术摘要：许多自旋电子现象和设备的核心是纯自旋电流或自旋极化电荷电流在非磁性金属中的流动。在这种情况下，一个基本的问题是，非平衡自旋布居在非磁性金属中松弛的距离是多少，或者自旋扩散长度是多少？值得注意的是，尽管控制金属自旋弛豫的基本机制--Elliot-Yafet机制是已知的，但我们对这一过程的理解仍然存在巨大的差距。具体缺陷的个体影响仍然未知，阻碍了对自旋输运的定量或预测性理解。解决这一问题具有明显的技术相关性，将是一项变革性的进步。这个项目的实质是使用非局部横向自旋阀来确定各种常规金属和氧化物基金属中的自旋扩散长度。人们正在研究像Al这样的元素金属，以分别量化由于声子、杂质、晶界、表面和界面引起的自旋弛豫，从而确定每个缺陷的Elliott-Yafet常数。金属钙钛矿氧化物也在研究中。这些材料为自旋电子学提供了巨大的潜力，尽管对它们的自旋扩散长度的了解仍然难以捉摸。这项研究跟踪了从传统金属基器件到钙钛矿型金属的进展，首次了解了氧化物铁磁体和非磁性金属中的自旋扩散长度，这是氧化物自旋电子学发展的关键一步。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。