Magnetoelectric responses from the respective magnetic R and Fe subsystems in the noncentrosymmetric antiferromagnets RFe3(BO3)4 (R = Eu, Gd, and Tb)
Magnetoelectric responses from the respective magnetic R and Fe subsystems in the noncentrosymmetric antiferromagnets RFe3(BO3)4 (R = Eu, Gd, and Tb)
复制标题
非中心对称反铁磁体 RFe3(BO3)4 中各自磁性 R 和 Fe 子系统的磁电响应（R = Eu、Gd 和 Tb）
DOI：
10.1103/physrevb.89.195126
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发表时间：
2014
影响因子：
3.7
通讯作者：
and Y. Tokura
中科院分区：
文献类型：
--
作者：
T. Kurumaji;K. Ohgushi;and Y. Tokura
在稀土（）硼酸铁中，R() R= Eu， Gd和Tb，磁电（ME）响应似乎源于铁（Fe）自旋的反铁磁顺序和离子上的磁矩。我们测量了沿轴的电极化（），同时绕轴旋转磁场（），发现目标化合物表现出相互不同的方向依赖性。（）（R= Eu）显示出几乎恒定的自发性，当它从轴线倾斜时有轻微的调制。角的依赖关系可以用一个公式来描述。（）和（）表现出高度的各向异性依赖，这表征了它们各自的磁矩对ME的响应。在的某些区域，可以分别用和来表示r = Gd和Tb。我们为aR（）晶体中单个磁性离子的ME响应设计了一个理论，并将其应用于这些化合物，重点关注它们的局部对称性和基态多重结构。上述公式成功地将观测结果作为每个磁子系统的总和再现，从而使我们能够将第一项和第二项分别分配给铁自旋的共线反铁磁顺序和离子的ME响应。磁性离子的热演化和诱导演化在定量上与理论预测一致，确保了每个磁性离子的相关微观ME机制。角相关性的测量对于在具有多个磁子系统的系统中将重叠的电磁响应分解为各自的原点特别有用。
In rare-earth () ferroborates,R()withR= Eu, Gd, and Tb, the magnetoelectric (ME) responses appear to stem from both the antiferromagnetic order of the iron (Fe) spins and the magnetic moments on theions. We measured the electric polarization () along theaxis while rotating a magnetic field () around theaxis and found that the target compounds show mutually distinctive-direction dependencies.()(R= Eu) shows an almost constant spontaneouswith a slight modulation whenis slanted from theaxis. The-angle () dependence of thecan be described by a formula. As for()and(), they show highly anisotropicdependence of, which characterizes the respective ME responses from theirmagnetic moments. In certain regions of, thecan be described byandforR= Gd and Tb, respectively. We devised a theory for the ME response of the individual magnetic ions in aR()crystal and applied it to these compounds focusing on their local symmetry and their ground-state multiplet structures. The above formulas successfully reproduce the observed results as the summation offrom each magnetic subsystem, which in turn enables us to assign the first and second terms to the spontaneousdue to a collinear antiferromagnetic ordering of the Fe spins and the ME response of theion under, respectively. The thermal and-induced evolutions of the magnetic-ion resolvedquantitatively agree with the theoretical predictions, ensuring the relevant microscopic ME mechanism for each magnetic ion. The measurement of angular dependence ofis particularly useful to decompose the overlapped ME responses into the respective origins in the system with multiple magnetic subsystems.