Nuclear probes of magnetic order

磁序核探针

• 批准号: 42310-2013
• 负责人: Ryan, Dominic
• 金额: $ 2.33万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633564
• 关键词: Nuclear; probes; magnetic; order

Rare earth magnets are now ubiquitous, being used in motors and actuators anywhere electricity is converted into motion. Examples range from motors in disc drives, moving both the disc and the read/write head, motors in portable power tools (drills, saws, drivers, etc...), remote door locks on cars. They touch every aspect of our modern technology. The material that enabled this revolution is the rare earth/iron compound Nd2Fe14B. This was discovered in the early 1980s as part of fundamental research on rapidly quenched liquid metals in which I was involved.In my work I seek to understand how things become magnetic - where their magnetic moment comes from - and how they order -- how, once the moment has formed, those moment choose to arrange themselves in a magnetic material. While my work is primarily fundamental in nature, a proper understanding of these basic issues is essential to the development of new, high performance magnetic materials.Over the next five years I will be concentrating on a group of rare earth based materials that are widely regarded as "off limits" or at least very difficult to study. However, as a result of techniques that I developed in collaboration with scientists at the Canadian Neutron Beam Centre, we have been able to open these materials to more detailed study. I will be looking at marginal magnetic materials based on samarium, europium and ytterbium where the magnetic moments are just forming and are easily affected by changes in materials chemistry. I will also be looking at very well defined moments on gadolinium compounds where experimental difficulties had previously precluded detailed study.

稀土磁体现在无处不在，用于将电力转化为运动的任何地方的电机和执行器。示例包括磁盘驱动器中用于移动磁盘和读/写头的电机、便携式电动工具（钻头、锯、驱动器等）中的电机、汽车上的远程门锁。它们涉及现代技术的各个方面。促成这场革命的材料是稀土/铁化合物 Nd2Fe14B。这是在 20 世纪 80 年代初发现的，作为我参与的快速淬火液态金属基础研究的一部分。在我的工作中，我试图了解事物如何变得有磁性——它们的磁矩从何而来——以及它们如何排序——一旦磁矩形成，这些磁矩如何选择在磁性材料中排列自己。虽然我的工作本质上主要是基础性的，但正确理解这些基本问题对于开发新型高性能磁性材料至关重要。在接下来的五年里，我将专注于一组被广泛认为“禁区”或至少很难研究的稀土材料。然而，由于我与加拿大中子束中心的科学家合作开发的技术，我们已经能够对这些材料进行更详细的研究。我将研究基于钐、铕和镱的边缘磁性材料，其中磁矩刚刚形成，很容易受到材料化学变化的影响。我还将研究钆化合物的非常明确的时刻，以前由于实验困难而无法进行详细研究。