Spin-Diffusion in Magnetic Multilayer Structures

*非技术摘要*电子有两种特性，使它们成为许多电子设备中的主要元素。这些性质是它们的电荷和所谓的电子自旋，即它们各自产生磁场的事实。只有当所有或大部分电子自旋在导电材料-金属中对准或反对准时，该材料的特性才存在，即所谓的铁磁性或反铁磁性。这个项目将研究在不同类型的金属层中扩散时，自旋从磁性状态变得有序或无序需要多长时间。这些研究将确定磁性状态在样品层中松弛或扩散的速度。这种材料的这些性质对“自旋电子学”非常重要。自旋电子学是一种新型设备的名称，它根据电子的自旋和电荷的性质工作，而不是像目前半导体电子学中使用的那样，仅仅依靠电荷工作。该项目将教育活动无缝地融入各级教育的研究计划中。此外，将在夏季继续通过现有的讲习班向历史上黑人学院和大学(HBCU)的教职员工进行外联工作。*磁性多层膜结构中的磁化驰豫对于它们在自旋电子器件中的应用至关重要，包括读取头、磁性随机存取存储器和自旋扭矩振荡器。更好地理解驰豫机制将有助于进一步优化用于自旋电子应用的磁性多层结构。这项工作将结合矢量网络分析仪铁磁共振(VNA-FMR)和短波导铁磁共振技术，在较宽的频率范围内获得磁性多层结构的磁化动力学和磁化驰豫的信息。这项工作的三个主要目的是研究掺杂对铜薄膜自旋扩散的影响，确定金属/金属界面的自旋反转几率，以及研究金属反铁磁体中的自旋扩散。该项目将教育活动无缝地融入各级教育的研究计划中。此外，将在夏季继续通过现有的讲习班向历史上黑人学院和大学(HBCU)的教职员工进行外联工作。

****NON-TECHNICAL ABSTRACT****Electrons have two properties that make them the prime elements in many electronic devices. These properties are their electrical charge and what is known as electron spin, the fact that they individually produce a magnetic field. It is when all or most of the electron spins are aligned or anti-aligned in an electrically conducting material, a metal, that properties of that material known as ferromagnetism or anti-ferromagnetism exists. This project will investigate how long the spins take to become ordered or disordered from a magnetic state while diffusing through layers of different types of metals. The studies will determine the rate at which the magnetic state relaxes or diffuses through the sample layers. These properties of the material are of high importance to "spintronics". Spintronics is the name of a new type of device operating on the properties of the electron spin and charge rather than just on the charge as is currently used in semiconductor electronics. This project seamlessly integrates educational activities into the research program at all levels of education. In addition outreach efforts to faculty members from historically black colleges and universities (HBCUs) through an existing workshop during the summer months will continue. **** TECHNICAL ABSTRACT****The magnetization relaxation in magnetic multilayer structures is of crucial importance for their application in spintronic devices including read-heads, magnetic random access memories and spin-torque oscillators. A better understanding of the relaxation mechanisms will enable further optimization of the magnetic multilayer structures for spintronic applications. This work will combine the techniques of vector-network analyzer ferromagnetic resonance (VNA-FMR) and shorted waveguide ferromagnetic resonance to obtain information about the magnetization dynamics and the magnetization relaxation in magnetic multilayer structures over a wide frequency range. The three main thrusts of the proposed work are the investigation of the influence of doping on the spin-diffusion in thin copper films, the determination of the interfacial spin-flip probability at metal/metal interfaces and the investigation of spin-diffusion in metallic antiferromagnets. This project seamlessly integrates educational activities into the research program at all levels of education. In addition outreach efforts to faculty members from historically black colleges and universities (HBCUs) through an existing workshop during the summer months will continue.