Relaxor ferroelectricity induced by electron correlations in a molecular dimer Mott insulator
Relaxor ferroelectricity induced by electron correlations in a molecular dimer Mott insulator
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分子二聚体莫特绝缘体中电子关联引起的弛豫铁电
DOI：
10.1103/physrevb.87.075107
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
and T. Sasaki
中科院分区：
文献类型：
--
作者：
S. Iguchi;S. Sasaki;N. Yoneyama;H. Taniguchi;T. Nishizaki;and T. Sasaki
本文研究了具有正方二聚体晶格的反铁磁二聚体-Mott绝缘体-（BEDT-TTF）ICl的介电响应，并与自旋液体候选物-（BEDT-TTF）Cu（CN）进行了比较.介电常数的温度依赖性表现出一个峰结构服从居里-外斯定律，具有很强的频率依赖性。通过热释电测量发现了各向异性的玻璃态铁电性，这表明二聚体中的电荷极化导致了电偶极子。每个铁电和反铁磁转变温度是密切相关的反铁磁相互作用能和偶极子动力学的冻结温度，分别在一个二聚体。这些对应关系表明了系统中可能存在的电荷-自旋耦合自由度。
We have investigated the dielectric response in an antiferromagnetic dimer-Mott insulator’-(BEDT-TTF)IClwith square dimer lattice, compared to a spin liquid candidate-(BEDT-TTF)Cu(CN). Temperature dependence of the dielectric constant shows a peak structure obeying Curie-Weiss law with a strong frequency dependence. We found an anisotropic glassy ferroelectricity by pyrocurrent measurements, which suggests the charge disproportionation resulting in an electric dipole in a dimer. Each ferroelectric and antiferromagnetic transition temperature is closely related to the antiferromagnetic interaction energy and a freezing temperature of dipole dynamics in a dimer, respectively. These correspondences suggest the possible charge-spin coupled degrees of freedom in the system.