Coupling Influences SMM Properties for Pure 4 f Systems
Coupling Influences SMM Properties for Pure 4 f Systems
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耦合影响纯 4 f 系统的 SMM 属性
DOI：
10.1002/chem.201705350
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Powell Annie K.
中科院分区：
文献类型：
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作者：
Zhang Xuejing;Liu Shuang;Vieru Veacheslav;Xu Na;Gao Chen;Wang Bing-Wu;Shi Wei;Chibotaru Liviu F.;Gao Song;Cheng Peng;Powell Annie K.
增加磁化反转的能垒和磁滞回线的矫顽场是单分子磁体（SMM）领域的重大挑战。稀土离子的配位几何结构和稀土离子之间的磁相互作用对于引导 SMM 的磁性行为都很重要。我们报告了具有约束双蝶对称性（D2d）的抗磁性离子稀释的镧系元素链化合物的高能垒为 657 K（457 cm−1）；该能垒远高于具有链内铁磁相互作用的非稀释链化合物的 567 K (394 cm−1) 的能垒。尽管链内磁相互作用降低了磁化反转的能垒，但它可以大大增强磁滞回线的矫顽场和零场剩磁，这对于高性能SMM的合理设计至关重要。通过从头计算揭示了与镧系元素中心的配位球相关的因素，这些因素通过第二激发的克莱默双峰控制高磁弛豫势垒以及影响磁滞回线的磁相互作用。
Increasing both the energy barrier for magnetization reversal and the coercive field of the hysteresis loop are significant challenges in the field of single‐molecule magnets (SMMs). Coordination geometries of lanthanide ions and magnetic interactions between lanthanide ions are both important for guiding the magnetic behavior of SMMs. We report a high energy barrier of 657 K (457 cm−1) in a diamagnetic‐ion‐diluted lanthanide chain compound with a constrained bisphenoid symmetry (D2d); this energy barrier is substantially higher than the barrier of 567 K (394 cm−1) of the non‐diluted chain compound with intrachain ferromagnetic interactions. Although intrachain magnetic interaction lowers the energy barrier for magnetization reversal, it can greatly enhance the coercive fields and zero‐field remanence of the hysteresis loops, which is crucial for the rational design of high‐performance SMMs. Factors related to the coordination sphere of the lanthanide center, which govern the high magnetic relaxation barriers through the second excited Kramer's doublets and the magnetic interactions that affect the hysteresis loops, were revealed through ab initio calculations.