Synthesis and Magnetism of Rare Earth Nanostructures

9424339弗林我们 探索 并控制磁行为 的 稀土纳米结构 这些材料是由稀土金属片叠合成的，通过分子束外延技术调整厚度和含量。 大块稀土具有丰富的特殊磁性，包括独特的螺旋磁化和大的磁致伸缩。 拟议的研究包括这些新材料配置的结构，磁性，磁性微结构和磁输运的研究。 利用中子散射、X射线散射和 同步辐射，SQUID磁力测量， 和 光刻处理结构的传输测量。 特别感兴趣的是：磁相稳定性和薄膜微结构的控制;新的磁性纳米结构的化学合成;界面附近的磁耦合的预测;和变换动力学，包括波动和非弹性过程。 我们专注于磁性纳米结构的合成和性能， 从 分子束表面稀土金属 层沉积。 这种受控工艺在晶体衬底上逐层组装薄膜，由选定的元素金属制成，以高质量单晶的形式，具有连续层的设计化学顺序。 对稀土金属的关注 对它们的磁性行为的技术和科学兴趣。 我们能够定制选定的结构，使我们能够探索原子磁矩之间的相互作用，导致丰富多样的磁性结构。 表面层沉积工艺通过将膜夹持到衬底上以及通过所产生的应变和薄膜几何形状对磁性具有控制影响。 控制这些材料的磁行为的能力与存储器的应用有关， 开关和使用薄膜磁性器件的信息操纵。 ***

9424339 Flynn We explore and control the magnetic behavior of rare-earth nanostructures. These are synthesized from rare-earth metals as stacks of sheets, tailored in thickness and content by molecular beam epitaxy. Bulk rare earths exhibit a rich variety of unusal magnetic behavior, including unique helimagnetism and large magnetostriction. The proposed research includes studies of structure, magnetism, magnetic microstructure, and magnetotransport in these novel materials configurations. Use is made of neutron scattering, x-ray scattering with synchrotron radiation, SQUID magnetometry, and transport measurements on lithographically processed structures. Of special interest are: control of magnetic phase stability and thin film microstructure; chemical synthesis of new magnetic nanostructures; prediction of magnetic couplings near interfaces; and transformation dynamics including fluctuation and inelastic processes. %%% We focus on the synthesis and properties of magnetic nanostructures made from rare-earth metals by molecular beam surface layer deposition. This controlled process assembles thin films layer by layer on a crystalline substrate, from selected element metals, in the form of high quality single crystals, with a designed chemical sequence of successive layers. The focus on rare-earth metals is driven by technical and scientific interest in their magnetic behavior. Our abiliity to tailor selected structures allows us to explore the interactions among the atomic magnetic moments that cause a rich variety of magnetic structures. The surface layer deposition process has a controlling influence on magnetism through the clamping of the film to the substrate, and through the resulting strain and thin film geometry. The ability to control magnetic behavior of these materials is of interest in connection with applications to the storage, switching, and manipulation of information using thin film magnetic devices. ***