Thermodynamically stable skyrmion lattice at low temperatures in a bulk crystal of lacunar spinel GaV4Se8
Thermodynamically stable skyrmion lattice at low temperatures in a bulk crystal of lacunar spinel GaV4Se8
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DOI：
10.1103/physrevb.95.180410
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发表时间：
2017-05-30
影响因子：
3.7
通讯作者：
Arima, T.
中科院分区：
文献类型：
--
作者：
Fujima, Y.;Abe, N.;Arima, T.
通过交流磁化率和磁电测量以及经典的Monte Carlo模拟，确定了GaV_4Se_8的磁场-温度（H-T）相图。GaV_4Se_8在结构相变温度T_S = 41 K以下是热释电的，在T_C = 17.5 K以下是磁有序的。交流磁化率测量表明，随着外加磁场的增加，GaV_4Se_8发生连续的磁相变。每个阶段被分配到摆线，skyrmion晶格，和强迫铁磁相。摆线和skyrmion晶格磁序诱导电极化高达约10 μ C/m（2）相比，铁磁序，表明自旋驱动的磁电性质在GaV 4Se 8。skyrmion晶格相似乎是稳定的，T = 2 K和高达μ H-0 = 370 mT。与GaV_4S_8相比，GaV_4Se_8中skyrmion晶格的稳定性增强，这可能为理解skyrmion晶格的形成机制提供了一把钥匙。
The magnetic field-temperature (H-T) phase diagram of a lacunar spinel GaV4Se8 is determined by means of ac magnetic susceptibility and magnetoelectric measurements on single crystals and classical Monte Carlo simulation. GaV4Se8 is pyroelectric below the structural phase transition temperature T-S = 41 K and magnetically ordered below T-C = 17.5 K. Ac magnetic susceptibility measurement has revealed that GaV4Se8 undergoes successive magnetic phase transitions with increasing applied magnetic field. Each phase is assigned to cycloidal, skyrmion lattice, and forced ferromagnetic phases. Both cycloidal and skyrmion-lattice magnetic orders induce electric polarization up to around 10 mu C/m(2) compared with ferromagnetic order, suggesting a spin-driven magnetoelectric nature in GaV4Se8. The skyrmion lattice phase seems to be stable down to T = 2 K and up to mu H-0 = 370 mT. This enhanced stability of skyrmion lattice in GaV4Se8 compared with GaV4S8 may provide a key to understanding the formation mechanism of the skyrmion lattice.