High magnetic field induced phases and half-magnetization plateau in the S=1 kagome compound Ni(3)V(2)O(8)
High magnetic field induced phases and half-magnetization plateau in the S=1 kagome compound Ni(3)V(2)O(8)
复制标题
DOI：
10.1103/physrevb.84.220407
复制
发表时间：
2011-12
影响因子：
3.7
通讯作者：
Junfeng Wang;M. Tokunaga;Zhangzhen He;J. Yamaura;A. Matsuo;K. Kindo
中科院分区：
文献类型：
--
作者：
Junfeng Wang;M. Tokunaga;Zhangzhen He;J. Yamaura;A. Matsuo;K. Kindo
本文报道了一种$S$$=$ 1 kagome化合物——Ni ${}_{3}$ V ${}_{2}$ O ${}_{8}$的单晶磁化、电极化和比热的强磁场研究。当磁场平行于磁易轴时，磁化过程呈现多步磁跃迁。在饱和磁化高度的一半处观察到明显的磁化平台${M}_{\mathrm{s}}$\ensuremath{\sim} 2.39 \ensuremath{\mu}${}_{\mathrm{B}}$ /Ni。此外，高场下的磁化跃迁在${M}_{\mathrm{s}}$的2/3、3/4和8/9处量子化。这些结果对于理论预测的传统kagome反铁磁体的三分之一磁化平台来说是不寻常的。我们发现高磁场抑制了自发极化，导致不同的高场相，其中磁结构与底层晶格共线或共面。由此产生的高场相图探索了几个磁相，并阐明了最近的实验发现。本文提出了分析论点来讨论这些高场相。
We report on high magnetic field studies of magnetization, electric polarization, and specific heat on single crystals of Ni${}_{3}$V${}_{2}$O${}_{8}$, which is an $S$ $=$ 1 kagome compound. The magnetization process exhibits multistep magnetic transitions when the magnetic field is parallel to the magnetic easy axis. An apparent magnetization plateau was observed at half the height of the saturation magnetization ${M}_{\mathrm{s}}$ \ensuremath{\sim} 2.39\ensuremath{\mu}${}_{\mathrm{B}}$/Ni. In addition, the magnetization transitions at higher fields are quantized at 2/3, 3/4, and 8/9 of ${M}_{\mathrm{s}}$. These results are unusual for the one-third magnetization plateaus that theories have predicted for conventional kagome antiferromagnets. We find that the high magnetic field suppresses the spontaneous polarization, leading to a different high-field phase where the magnetic structure is collinear or coplanar with the underlying lattice. The resulting high-field phase diagram explores several magnetic phases and sheds light on recent experimental findings. Analytical arguments have been presented to discuss these high-field phases.