发表机构
School of Physics and Technology, Nanjing Normal University; State Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), University of Science and Technology of China（南京师范大学物理科学与技术学院; 中国科学技术大学化学与材料科学学院精密与智能化学国家重点实验室及化学为能源材料协同创新中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出在柔性d0金属有机框架中，通过极性取代基耦合电场驱动配体旋转，实现反铁磁至交变磁性的可逆切换，为有机自旋电子学提供电场控制途径。
AI 中文摘要
交变磁性结合了消失的净磁化强度与动量相关的自旋分裂。尽管已在金属有机框架（MOFs）中识别出交变磁性特征，但非侵入式可逆控制仍具挑战性。本文报道了一种在柔性d0-MOF中实现电场可切换交变磁性的途径，其中极性取代基将外场耦合至配体旋转。在平面基态中，pz轨道介导180度配体-金属-配体超交换（J2），稳定反铁磁序。将配体旋转出平面会激活px/py轨道，增强90度路径（J1），并反转J1/J2竞争。反铁磁到交变磁性的交叉发生在约34度处，90度时自旋分裂为84 meV。90度交变磁性状态由电场开启，并在撤去电场后关闭，因为受限旋转势能面单调回落至0度，实现无障碍弛豫至反铁磁态及可逆开关操作。300 K下的从头算分子动力学表明，热涨落本身无法同步配体旋转。极性取代基提供了电场控制所需的耦合；对于氟化取代基，临界场约为0.22 V/埃，与场效应器件相当。这项工作确立了配体p轨道（而非过渡金属d轨道）作为交变磁序的起源，并表明极性取代基可实现有机自旋电子学的电场控制。
英文摘要
Altermagnetism combines vanishing net magnetization with momentum-dependent spin splitting. While altermagnetic signatures have been identified in metal-organic frameworks (MOFs), non-invasive reversible control remains challenging. Here we report a route to electric-field-switchable altermagnetism in a flexible d0-MOF, in which polar substituents couple the external field to ligand rotation. In the planar ground state, pz orbitals mediate 180-degree ligand-metal-ligand superexchange (J2), stabilizing antiferromagnetic order. Rotating ligands out of plane activates px/py orbitals, enhances 90-degree pathways (J1), and reverses J1/J2 competition. The antiferromagnetic-to-altermagnetic crossover occurs at approx. 34 degrees, with spin splitting of 84 meV at 90 degrees. The 90-degree altermagnetic state is switched on by the electric field and switched off upon field removal, as the constrained-rotation landscape decreases monotonically back toward 0 degrees, enabling barrierless relaxation to the antiferromagnetic state and reversible on/off operation. Ab initio molecular dynamics at 300 K shows thermal fluctuations alone cannot synchronize ligand rotation. Polar substituents provide the required coupling for electric-field control; for fluorinated substituents, the critical field is approx. 0.22 V/Angstrom, comparable to field-effect devices. This work establishes ligand p orbitals, rather than transition-metal d orbitals, as the origin of altermagnetic order and shows that polar substituents enable electric-field control for organic spintronics.
