Materials World Network: Magnetic Properties of Mesoscopic Multilayer Rings

微电子设备正在发展，以包括广泛的非传统材料，这些材料提供了标准半导体材料集所不具备的功能。具体地说，磁性材料的结合允许制造一系列新的磁电子器件，例如磁随机存取存储器和磁阻读回头。该项目探索介观多层环中的材料问题，以期将其应用于未来的磁电子器件。薄膜多层环将作为研究磁性行为的试验台。环是理想的，有几个原因：它们可以被磁化以具有一系列的磁化壁几何形状，或者没有壁；它们不像在细长的薄膜结构中看到的那样具有端域；并且它们具有各种可能的磁化状态，这些磁化状态可以适合于在存储器件中存储多个比特。将制作不同几何形状、微结构和层序的环，并将利用磁光测量、光散射和磁阻测量来研究其磁化状态、静态行为和动态行为，并与成分和层序、微结构和加工有关。这是麻省理工学院的研究人员和布兰德教授以及英国剑桥大学的合作者共同完成的一个项目。这项工作的更广泛影响包括培训、联合教育活动，如远程学习，以及为高中教学开发示范材料，充分利用合作的国际性。

Microelectronic devices are evolving to include a wide range of non-traditional materials which provide functionality not available in the standard semiconductor materials set. In particular, incorporation of magnetic materials allows a range of new magnetoelectronic devices to be built, for example magnetic random access memories and magnetoresistive readback heads. This project explores materials issues in mesoscopic multilayer rings, with a view to their incorporation in future magnetoelectronic devices. Thin-film multilayer rings will be used as a test bed for studying magnetic behavior. Rings are ideal for several reasons: they can be magnetized to have a range of domain wall geometries, or no walls; they do not have end domains as seen in elongated thin film structures; and they have a variety of possible magnetization states which could be suitable for storage of multiple bits in a memory device. Rings of different geometries, microstructures and layer sequences will be made, and their magnetization states, static behavior and dynamic behavior will be investigated using magnetooptical measurements, light scattering, and magnetoresistance measurements, and related to composition and layer sequence, microstructure and processing. This is a collaborative project between researchers in MIT and Prof. Bland and collaborators in Cambridge University, UK. The broader impacts of the work include training, joint educational activities such as distance learning, and development of demonstration materials for high school teaching, taking full advantage of the international nature of the collaboration.