Microwave Losses and Interactions in Patterned Magnetic Nanostructures

本研究的目的是提供一个更深入的了解机制，在纳米磁性系统，如阵列光刻图案化的纳米结构的高频损耗。该方法是使用铁磁共振（FMR）和静态磁测量，以调查的磁化率，开关场分布，和共振线宽，这些量之间的关系，以及从纳米磁体之间的相互作用，这些属性的贡献。在小的磁性元件内，自旋波和静磁模式被激发，并且元件的属性的统计分布使得这样的系统在激发带上有损耗。灵敏的FMR和宽带测量将揭示这些模式并提供损耗数据。这项工作很重要，因为小磁性颗粒在未来的极高密度存储，传感器阵列和磁性随机存取存储器等应用中发挥着关键作用。当磁性元件的尺寸减小时，操作速度增加。因此，了解高频性能和损耗的问题变得至关重要。这一建议的更广泛影响包括：培训研究生和本科生;将研究知识纳入麻省理工学院和乔治华盛顿大学教授的课程;通过教育推广活动展示研究、发现、其应用和社会效益之间的关系，在非理科专业和女高中生中推广科学和技术。这将通过在高中举行的关于磁盘驱动器、晶体管或光纤等关键技术设备的讲座和演示来进行。

The objective of this research is to provide a deeper understanding of the mechanism of high frequency losses in nanoscale magnetic systems such as arrays of lithographically-patterned nanostructures. The approach is to use ferromagnetic resonance (FMR) and static magnetic measurements to investigate the coercivity, switching field distribution, and resonance linewidth, the relationship between these quantities, and the contribution from interactions between the nanomagnets to these properties. Within small magnetic elements, spin waves and magnetostatic modes are excited, and the statistical distribution of properties of the elements make such systems lossy over a band of excitations. Sensitive FMR and broadband measurements will reveal these modes and provide loss data. Intellectual MeritThis work is important because small magnetic particles play a critical role in applications such as future extreme high density storage, sensor arrays, and magnetic random access memories. While the size of the magnetic elements is decreasing, the speed of operation is increasing. As a result, understanding the problem of high frequency performance and losses becomes essential. The broader impacts of this proposal include the training of graduate and undergraduate students; the incorporation of research knowledge into classes taught in both MIT and GWU; and the demonstration of the relation between research, discovery, its application and societal benefits by educational outreach activity to promote science and technology among non-science majors and female high school students. This will be carried out through talks and demonstrations of technologically critical devices such as disk drives, transistors or optical fibers, presented in high schools.