Bottom-Up Manufacturing of Sustainable Magnetic Nanocrystal Assembly

单分散（均匀尺寸）磁性纳米晶已成功地应用于高能量密度磁体、数据存储和生物技术应用。然而，由于纳米晶体中存在不同类型的平面缺陷，因此实现大规模所需的有序结构仍然是一个挑战。本计画的目的是利用自下而上的核/壳互扩散法，以奈米级的精度，制备并研究亚稳态、外延稳定的无稀土磁性铁奈米晶。高能量密度的磁性纳米复合材料将通过硬磁和软磁纳米晶体的自组装交换耦合（磁相互作用）来开发，这将通过高通量微波处理来扩大规模。最终目标是展示一种自下而上的制造策略，以发现不含稀土的高能量密度磁性纳米材料。这项研究将为磁性合金纳米晶体提供一条多功能的纳米制造路线，并对其结构进行前所未有的控制，并为操纵自下而上的组装控制交换耦合过程创造一条合理的途径。此外，从低成本元素（如铁和镍）中发现不含稀土的高能量密度纳米磁体代表了当前和未来可持续高能量密度应用的关键部分，包括更小，更轻和更高效的电动机和发电机，以及非侵入性磁热疗生物技术。成功开发的铁基弹簧纳米磁体将（1）减少美国对稀土进口的依赖;（2）降低成本并提高高能量密度应用的效率;（3）确立美国在广泛采用绿色能源技术方面的领导地位。此外，对社会的好处是，成功的结果将导致地球丰富的材料和环境友好的制造应用的进步。

Monodispersed (uniform size) magnetic nanocrystals have been successfully applied in high energy density magnet, data storage and biotechnology applications. However, it has remained a challenge to achieve the ordered structure needed in a large scale due to different types of planar defects in the nanocrystals. The objective of this project is to produce and study metastable, epitaxially stabilized rare-earth-free magnetic ferrous nanocrystals using bottom-up core/shell interdiffusion process with nanoscale precision. High energy density magnetic nanocomposites will be developed through the self-assembled exchange-coupling (magnetic interaction) of magnetically hard and soft nanocrystals, which will be scaled up by high-throughput microwave processing. The ultimate goal is to demonstrate a bottom-up manufacturing strategy to discover rare-earth-free high-energy density magnetic nanomaterials. This study will represent a versatile nanomanufacturing route for magnetic alloy nanocrystals with unprecedented control of their structures, and create a rational pathway for manipulating bottom-up assembly-controlled exchange-coupling processes. In addition, discovering rare-earth-free high energy density nanomagnets from low cost elements, such as iron and nickel, represent a critical part of present and future sustainable high energy density applications, including smaller, lighter and more efficient motors and generators, as well as non-invasive magnetic hyperthermia biotechnology. A successfully developed ferrous based spring nanomagnets will (1) reduce the U.S. dependence on rare-earth imports; (2) reduce cost and improve efficiency of high energy density applications; and (3) establish U.S. leadership in a wide adoption of green energy technologies. In addition, the benefit to society is that successful results will lead to advances in earth abundant materials and environmentally benign manufacturing applications.