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.