稀土磁性材料磁结构的中子研究进展

Progress in neutron studies on the magnetic structures of rare earth magnetic materials

摘要:

稀土磁性材料凭借其4f电子独特的强自旋-轨道耦合、高原子磁矩及丰富电子能级,在永磁、磁致冷等高新技术领域具有不可替代的战略地位。稀土磁性材料中电子交换作用、磁多极相互作用与晶体场效应的多重竞争机制给揭示磁相变机制与量子激发行为带来本质性挑战。中子散射技术以其磁矩敏感性、强穿透性和轻元素分辨能力,成为揭示稀土磁结构微观机制的核心手段,该技术已在稀土永磁材料矫顽力优化、磁致冷材料磁熵变调控等领域取得突破性进展。本文系统综述中子散射技术的原理方法及其在稀土磁性材料磁结构研究中的前沿应用,包括稀土过渡金属化合物、稀土阻挫磁体、稀土低维磁体等。希望为稀土磁性材料磁结构的进一步研究提供参考。

Abstract:

Rare-earth magnetic materials hold an indispensable strategic position in high-tech fields such as permanent magnets and magnetic refrigeration, owing to the unique characteristics of their 4f electrons: strong spin-orbit coupling, high atomic magnetic moments, and rich electronic energy levels. The multifaceted competitive mechanisms among electron exchange interactions, magnetic multipolar interactions, and crystal field effects in these materials present fundamental challenges to elucidating magnetic phase transition mechanisms and quantum excitation behaviors. Neutron scattering technology, distinguished by its sensitivity to magnetic moments, exceptional penetration capability, and ability to distinguish light elements, serves as a pivotal technique for revealing the microscopic mechanisms of magnetic structures in rare-earth systems. This technique has achieved breakthrough progress in areas including coercivity optimization of rare-earth permanent magnets and regulation of the magnetic entropy change in magnetocaloric materials. This article systematically reviews the fundamental principles and methodologies of neutron scattering technology alongside its cutting-edge applications in investigating magnetic structures within rare-earth magnetic materials, including rare-earth-transition-metal compounds, rare-earth frustrated magnets, and rare-earth low-dimensional magnets. The review aims to provide a foundational reference for advancing research on magnetic structures in rare-earth systems.