RUI: Relaxation in Magnetic Structures

非技术：磁性材料被用于非常广泛的应用--从硬盘系统中的磁性存储器到与卫星的高频通信，再到雷达系统。这些应用中的许多关键取决于磁化从一个方向改变到另一个方向并稳定在这个新方向上的速度。这个项目探索了稳定磁化和调整磁化变化速度的新方法。该项目的结果可以大大改进现有的应用，并更好地了解磁性材料。该项目还将研究和教育结合起来，以便对学生(研究生、本科生和高中生)进行高频学习所需的现代方法培训。所获得的技能，包括材料生长和表征，将帮助学生为在学术界、国家实验室和工业中的职业生涯做好准备。技术：本项目将研究几个磁系统中磁阻尼的基本方面。铁磁共振(FMR)是主要的工具之一，它提供有关单个薄膜或耦合薄膜的重要磁性参数(各向异性、有效磁化强度等)的信息。FMR还给出了吸收线的宽度，这对于弛豫研究是至关重要的。这项工作将研究四个相关项目：1)Fe和Py与杂质的体相和表面掺杂以控制损耗；2)探索在Fe/Cu多层膜中显著降低损耗；3)使用网络分析技术来阐明双磁振子散射的作用；4)Fe和混价磁性材料之间的衰减和交换耦合。从更广泛的角度来看，这项研究将有助于理解高频下的磁场动力学。这种信息对于提高磁存储器的写入速度以及用于雷达和卫星通信的高频信号处理至关重要。该项目还将研究和教育结合起来，以便对学生(研究生、本科生和高中生)进行高频学习所需的现代方法培训。

Non-Technical: Magnetic materials are used in an extraordinary range of applications - from magnetic memories in hard disk systems to high frequency communications with satellites to radar systems. Many of these applications depend critically on how fast the magnetization may be changed from one direction to another and stabilized in this new direction. This project explores new ways of stabilizing the magnetization and adjusting how fast the magnetization can change. The results of this project can lead to substantial improvements in existing applications and to a better understanding of magnetic materials. This project also integrates research and education in order to train students (graduate, undergraduate and high school) in modern methods required in high frequency studies. The acquired skills, which include material growth and characterization will help prepare the students for careers in academe, national laboratories, and industry.Technical:This project will study fundamental aspects of magnetic damping in several magnetic systems. One of the primary tools, ferromagnetic resonance (FMR), provides information about the important magnetic parameters (anisotropies, effective magnetization, etc) of an individual film or coupled films. FMR also gives the width of the absorption line that is of paramount importance for relaxation studies. This work will investigate four related projects: 1) Bulk and surface doping of Fe and Py with impurities to control damping; 2) Exploration of the dramatic lowering of the damping in Fe/Cu multilayers; 3) The use of Network Analyzer techniques to clarify the role of two-magnon scattering and 4) Damping and exchange coupling between Fe and mixed valence magnetic materials. From a broader perspective, the research will aid in understanding magnetic dynamics at high frequencies. Such information is central to improving the speed of writing in magnetic memories and to high frequency signal processing used in radar and satellite communications. This project also integrates research and education in order to train students (graduate, undergraduate and high school) in modern methods required in high frequency studies.