Pressure-Dependent Intermediate Magnetic Phase in Thin Fe3GeTe2 Flakes.
Pressure-Dependent Intermediate Magnetic Phase in Thin Fe3GeTe2 Flakes.
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DOI：
10.1021/acs.jpclett.0c01801
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Heshen Wang;Runzhang Xu;Cai Liu;Le Wang;Zhan Zhang;H. Su;Shanmin Wang;Yusheng Zhao;Zhaojun Liu;Dapeng Yu;J. Mei;Xiaolong Zou;J. Dai
中科院分区：
文献类型：
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作者：
Heshen Wang;Runzhang Xu;Cai Liu;Le Wang;Zhan Zhang;H. Su;Shanmin Wang;Yusheng Zhao;Zhaojun Liu;Dapeng Yu;J. Mei;Xiaolong Zou;J. Dai
利用原位磁性圆二色谱(MCD)研究了层状Fe3GeTe2薄片在不同压力和温度下的铁磁性演化。我们发现，在平面外磁场扫描下，磁滞回线的矩形形状可以维持在7 Gpa以下。在该压力以上，在低温区出现中间态，其信号为8字形的偏滞回线。同时，矫顽场和居里温度随压力的增加而降低，表明压力下的交换作用和磁晶各向异性减小。根据Jagla理论，中间相具有错综复杂的磁畴结构，这是由于交换作用与磁晶各向异性之比的增加所致。此外，我们的计算结果显示，在6 Gpa附近有一个微弱的结构转变，对应于对磁相互作用有很大影响的Fei-Fei键长的显著变化。详细分析了交换作用和磁晶各向异性随压力的变化趋势，与实验结果一致。
We investigated the evolution of ferromagnetism in layered Fe3GeTe2 flakes under different pressures and temperatures using in situ magnetic circular dichroism (MCD) spectroscopy. We found that the rectangle shape of hysteresis loop under an out-of-plane magnetic field sweep can sustain below 7 GPa. Above that pressure, an intermediate state appears at low temperature region signaled by an 8-shaped skew hysteresis loop. Meanwhile, the coercive field and Curie temperature decrease with increasing pressures, implying the decrease of the exchange interaction and the magneto-crystalline anisotropy under pressures. The intermediate phase has a labyrinthine domain structure, which is attributed to the increase of ratio of exchange interaction to magneto-crystalline anisotropy based on Jagla's theory. Moreover, our calculation results reveal a weak structural transition around 6 GPa that corresponds to a significant change in the FeI-FeI bond length, which has strong influences on magnetic interaction. Detailed analysis on exchange interaction and magneto-crystalline anisotropy with pressure shows consistent trend with experiments.