Spin-driven ferroelectricity in triangular lattice antiferromagnets ACrO2 (A=Cu, Ag, Li, or Na)
Spin-driven ferroelectricity in triangular lattice antiferromagnets ACrO2 (A=Cu, Ag, Li, or Na)
复制标题
DOI：
10.1103/physrevlett.101.067204
复制
发表时间：
2008-08-08
影响因子：
8.6
通讯作者：
Tokura, Y.
中科院分区：
文献类型：
--
作者：
Seki, S.;Onose, Y.;Tokura, Y.
研究了具有120度螺旋结构的三角晶格反铁磁体ACrO（2）（A=Cu，Ag，Li，Na）的介电和磁性之间的相关性.对于具有铜铁矿结构的A=Cu和Ag化合物，铁电极化以螺旋自旋顺序出现，这意味着铁电性和螺旋自旋结构之间的强耦合。另一方面，对于具有有序岩盐结构的A = Li和Na化合物，没有发现自发极化，而在向螺旋自旋有序态转变时可以观察到介电常数的明显异常。这一特征可以归因于具有相反矢量自旋手征的Cr自旋片层的交替堆叠所诱导的可能的反铁电态。
The correlation between the dielectric and magnetic properties is investigated on the triangular-lattice antiferromagnets ACrO(2) (A=Cu, Ag, Li, or Na) with a 120-degree spiral structure. For the A=Cu and Ag compounds with a delafossite structure, the ferroelectric polarization emerges with a spiral-spin order, implying strong coupling between ferroelectricity and the spiral-spin structure. For the A = Li and Na compounds with an ordered rock salt structure, on the other hand, no spontaneous polarization is discerned, while the clear anomaly in the dielectric constant can be observed upon the transition to the spiral-spin ordered state. This feature can be ascribed to the possible antiferroelectric state induced by the alternate stacking of the Cr-spin sheet with opposite vector spin chirality.