Che Yixuan, Chen Yilin, Liu Xin, Lv Haifeng, Wu Xiaojun, Yang Jinlong
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
JACS Au. 2025 Jan 15;5(1):381-387. doi: 10.1021/jacsau.4c01150. eCollection 2025 Jan 27.
Altermagnets, characterized by spontaneous spin-splitting without net magnetization, are challenging to realize due to their unique spin group symmetries. Two-dimensional (2D) magnetic metal-organic frameworks (MOFs), with tunable topologies and spins, offer promising platforms for achieving altermagnetism. In this study, we propose a general strategy to create 2D altermagnetic monolayers by bridging Cr with organic ligands exhibiting nonbonding molecular orbitals (NBMOs) based on the Hückel molecular orbital theory and first-principles calculations. Three 2D MOFs, namely, Cr(diz), Cr(-pyr), and Cr(-pid) (diz = 1,3-diazete, -pyr = pyrrolo[3,4-]pyrrole, -pid = pyrrolo[3,4-]isoindole), are constructed using this strategy and exhibit the altermagntic ground state. These MOFs possess the spin point group 4̅ 2 and exhibit critical temperatures reaching up to 183 K. Analyses of orbital symmetry and energy levels rationalize the presence of altermagnetism. Our findings highlight the critical role of NBMOs in realizing 2D-MOF-based altermagnets with enhanced critical temperatures.
交替磁体以无净磁化的自发自旋分裂为特征，由于其独特的自旋群对称性，难以实现。二维（2D）磁性金属有机框架（MOF）具有可调节的拓扑结构和自旋，为实现交替磁性提供了有前景的平台。在本研究中，我们基于休克尔分子轨道理论和第一性原理计算，提出了一种通过用具有非键分子轨道（NBMO）的有机配体桥接Cr来创建二维交替磁单层的通用策略。使用该策略构建了三种二维MOF，即Cr(diz)、Cr(-pyr)和Cr(-pid)（diz = 1,3-二氮杂环丁二烯，-pyr = 吡咯并[3,4-]吡咯，-pid = 吡咯并[3,4-]异吲哚），并表现出交替磁基态。这些MOF具有自旋点群4̅ 2，临界温度高达183K。对轨道对称性和能级的分析解释了交替磁性的存在。我们的研究结果突出了NBMO在实现具有更高临界温度的基于二维MOF的交替磁体中的关键作用。
