Huang Yulong, Zhang Qiang, Li Yuguang C, Yao Yu, Hu Yong, Ren Shenqiang
Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA.
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Adv Mater. 2023 Feb;35(5):e2208919. doi: 10.1002/adma.202208919. Epub 2022 Dec 27.
2D magnets provoke a surge of interest in large anisotropy in reduced dimensions and are promising for next-generation information technology where dynamic magnetic tuning is essential. Until recently, the crucial metal-organic magnet Cr(pyz) ·xLiCl·yTHF with considerable high coercivity and high-temperature magnetic order opens up a new platform to control magnetism in metal-organic materials at room temperature. Here, an in-situ chemical tuning route is reported to realize the controllable transformation of low-temperature magnetic order into room-temperature hard magnetism in Cr(pyz) ·xLiCl·yTHF. The chemical tuning via electrochemical lithiation and solvation/desolvation exhibits continuously variable magnetic features from cryogenic magnetism to the room-temperature optimum performance of coercivity (H ) of 8500 Oe and energy product of 0.6 MGOe. Such chemically flexible tunability of room-temperature magnetism is ascribed to the different degrees of lithiation and solvation that modify the stoichiometry and Cr-pyrazine coordination framework. Furthermore, the additively manufactured hybrid magnets show air stability and electromagnetic induction, providing potential applications. The findings here suggest chemical tuning as a universal approach to control the anisotropy and magnetism of 2D hybrid magnets at room temperature, promising for data storage, magnetic refrigeration, and spintronics.
二维磁体激发了人们对低维大各向异性的浓厚兴趣，有望应用于下一代动态磁调谐至关重要的信息技术领域。直到最近，具有相当高矫顽力和高温磁序的关键金属有机磁体Cr(pyz)·xLiCl·yTHF为室温下控制金属有机材料中的磁性开辟了一个新平台。在此，报道了一种原位化学调谐途径，以实现Cr(pyz)·xLiCl·yTHF中低温磁序向室温硬磁性的可控转变。通过电化学锂化和溶剂化/去溶剂化进行的化学调谐展现出从低温磁性到室温下矫顽力（H）为8500奥斯特、能量积为0.6兆高斯奥斯特的最佳性能的连续可变磁特性。室温磁性这种化学上灵活的可调性归因于锂化和溶剂化程度的不同，它们改变了化学计量和Cr-吡嗪配位框架。此外，增材制造的混合磁体表现出空气稳定性和电磁感应，具有潜在应用价值。此处的研究结果表明化学调谐是在室温下控制二维混合磁体各向异性和磁性的通用方法，有望应用于数据存储、磁制冷和自旋电子学领域。
