Field-induced quantum magnetism in the verdazyl-based charge-transfer salt [o-MePy-V-(p-Br)2]FeCl4
Field-induced quantum magnetism in the verdazyl-based charge-transfer salt [o-MePy-V-(p-Br)2]FeCl4
复制标题
Verdazyl 基电荷转移盐 [o-MePy-V-(p-Br)2]FeCl4 中的场致量子磁性
DOI：
10.1103/physrevb.98.224411
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发表时间：
2018
影响因子：
3.7
通讯作者：
Yamaguchi H.
中科院分区：
文献类型：
--
作者：
Iwasaki Y.;Kida T.;Hagiwara M.;Kawakami T.;Kono Y.;Kittaka S.;Sakakibara T.;Hosokoshi Y.;Yamaguchi H.
我们成功地合成了一种基于硫丙基的电荷转移盐，该盐具有自由基和阴离子。分子轨道计算表明，形成了由三种交换相互作用与两种不等价位点组成的非蜂窝晶格。此外，通过反铁磁（AF）相互作用，一个位点被自旋夹在中间。磁性质表明，自旋之间的主要自旋相互作用形成间隙单重态，其余自旋形成自旋顺序。磁化曲线在7 T左右呈线性增长，在7 T至40 T之间出现非常规的5/6磁化平台。我们讨论了与该化合物磁性相关的有效相互作用与（-MePy-V）之间的差异。我们通过anspin模型的平均场近似解释了低场线性磁化曲线。在较高的磁场区域，af二聚体可以再现5/6的磁化平台和随后的非线性增加，其中一个自旋位置施加了特定的内部场。低温低场状态下的ESR信号可以用传统的易轴各向异性双亚晶格AF共振模式来解释。这些结果表明，在低场经典行为和场致量子行为中，自旋之间的交换相互作用实现了非常规的磁性。
We successfully synthesized a verdazyl-based charge-transfer salt, which hason the radicalandon theanion.Ab initiomolecular orbital calculations indicate the formation of anhoneycomb lattice composed of three types of exchange interaction with two types of inequivalent sites. Further, theat one site is sandwiched byspins through antiferromagnetic (AF) interactions. The magnetic properties indicate that the dominant AF interactions between thespins form a gapped singlet state, and the remainingspins cause an AF order. The magnetization curve exhibits a linear increase up to approximately 7 T, and an unconventional 5/6 magnetization plateau appears between 7 and 40 T. We discuss the differences between the effective interactions associated with the magnetic properties of the present compound and (-MePy-V). We explain the low-field linear magnetization curve through a mean-field approximation of anspin model. At higher field regions, the 5/6 magnetization plateau and subsequent nonlinear increase are reproduced by theAF dimer, in which a particular internal field is applied to one of the spin sites. The ESR signals in the low-temperature and low-field regime are explained by conventional two-sublattice AF resonance modes with easy-axis anisotropy. These results demonstrate that exchange interactions betweenandspins inrealize unconventional magnetic properties with low-field classical behavior and field-induced quantum behavior.