Magnetoelectric transitions of a distorted triangular-lattice antiferromagnet in a magnetic field
Magnetoelectric transitions of a distorted triangular-lattice antiferromagnet in a magnetic field
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磁场中扭曲三角晶格反铁磁体的磁电转变
DOI：
10.1103/physrevb.84.054429
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Tota Nakamura
中科院分区：
文献类型：
--
作者：
M. Wakeshima;Y. Hinatsu;and K. Ohoyama;酒井章雄,河野 浩;Tota Nakamura
利用大规模蒙特卡罗方法模拟了自旋晶格模型在磁场中的磁电跃迁。该模型很好地解释了实验得到的RbCoBr的场-温度相图。确定了各相的磁结构。在零场的情况下观察到的同时磁电转换被发现只发生在低场区域，而磁过渡和电过渡去耦在高场区域。当自旋-晶格关联较弱时，出现非对称亚铁磁态和半亚铁磁态。前者是介于部分无序态和亚铁磁态之间的中间态。后一阶段的特点是由一个子晶格序参数与-订购模式。
Large-scale Monte Carlo simulations are performed to analyze magnetoelectric transitions of a spin-lattice model in a magnetic field. The model explains well an experimental field-temperature phase diagram of RbCoBr. The magnetic structure in each phase is determined. Simultaneous magnetoelectric transitions observed in the zero-field case are found to occur only in the low-field region, whereas magnetic transitions and electric transitions are decoupled in the high-field region. When the spin-lattice correlation is weak, an asymmetric ferrimagnetic state and a half-ferrimagnetic state appear. The former is the intermediate state between the partial-disordered state and the ferrimagnetic state. The latter phase is characterized by a sublattice order parameter with a--ordering pattern.