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.
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.
