The Effect of Long-range Dumbbell Ordering on the Properties and Microstructures of Rare Earth Permanent Magnets

该基金探索了过渡金属哑铃浓度，有序，微观结构和稀土永磁体系统的磁行为之间的相互关系，该系统基于CaCu 5型结构的结构衍生物。一个主要的目标是调查与Sm-Co，Pr-Co和Sm-Fe中的无序TbCu 7型和有序Th 2 Zn 17型结构之间的转换相关的各个方面。过渡金属哑铃浓度和配置的影响，包括长程有序度和有序模式将被研究的微结构/磁性能的关系。此外，将研究的效果，整体微观结构上的反转机制，在磁铁设计有晶粒结构范围从纳米尺度到微米尺度。该项目的一个目标是开发磁计量技术，将磁行为与微观结构特征联系起来。 最终，结果将提供从亚纳米到微米的长度尺度上稀土永磁体的各种原子结构/微观结构/磁性能关系的细节。稀土永磁体是技术进步不可或缺的一部分。 设备的进一步小型化、更多的电动汽车、更节能的电机以及改进的医学成像技术都需要永磁体具有更高的能量密度和在苛刻环境中的更高性能。全面了解结构和性能之间的相互关系以及对磁化反转过程的理解对于开发先进的永磁技术至关重要。 更广泛的影响包括研究生和本科生的教学和培训，代表性不足的群体参与科学和工程，以及通过使用布鲁克海文、阿贡和橡树岭国家实验室的设施发展基础设施。

This grant explores the interrelationship between transition metal dumbbell concentration, ordering, microstructure, and magnetic behavior of rare earth permanent magnet systems based on structural derivatives of the CaCu5-type structure. A major objective is to investigate various aspects associated with transformations between the disordered TbCu7-type and ordered Th2Zn17-type structures in Sm-Co, Pr-Co and Sm-Fe. The influences of the transition metal dumbbell concentration and configuration, including the degree of long-range order and the order pattern will be studied on the microstructure/magnetic properties relationship. In addition, the effect of the overall microstructure will be investigated on the reversal mechanism in magnets designed to have grain structures ranging from the nanoscale to the microscale. A goal of the project is to develop magnetic metrology techniques to tie the magnetic behavior to microstructural features. Ultimately, the results will provide details of the various atomic structure/microstructure/magnetic property relationships in rare earth permanent magnets over length scales ranging from sub-nanometer to micrometer.%%%Rare earth permanent magnets are integral to technological advancements. Further miniaturization of devices, more electric vehicles, more energy-efficient motors, and improved medical imaging technology all require permanent magnets with higher energy densities and improved performance in demanding environments. A complete understanding of the interrelationships between structure and properties and an understanding of the magnetization reversal process are critical to developing advanced permanent magnet technology. Broader impacts include teaching and training of graduate and undergraduate students, involvement of underrepresented groups in science and engineering, and development of infrastructure through use of facilities at Brookhaven, Argonne and Oak Ridge National Laboratories.***