Isostructural Mott transition in 2D honeycomb antiferromagnet V0.9PS3
Isostructural Mott transition in 2D honeycomb antiferromagnet V0.9PS3
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DOI：
10.1038/s41535-019-0178-8
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发表时间：
2019-03
影响因子：
5.7
通讯作者：
M. Coak;S. Son;D. Daisenberger;H. Hamidov;C. Haines;P. Alireza;A. Wildes;Cheng Liu;S. Saxena-S.-Saxe
中科院分区：
文献类型：
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作者：
M. Coak;S. Son;D. Daisenberger;H. Hamidov;C. Haines;P. Alireza;A. Wildes;Cheng Liu;S. Saxena-S.-Saxe
MPX 3系列磁性范德华材料（M表示第一行过渡金属，X为S或Se）目前在低维磁性和输运以及新型器件和技术应用方面受到广泛而强烈的关注，但钒化合物到目前为止还没有被研究超出其基本性质。通过高压X射线衍射和输运测量，观察到了蜂窝状反铁磁体V0.9PS3中的等结构Mott绝缘体-金属转变.我们观察到绝缘可变范围跳跃型电阻率在V0.9PS3，随着压力的增加，有效维数逐渐增加，随后过渡到金属电阻率温度依赖性在112和124千巴之间。金属态还显示出低温上升，我们暂时归因于近藤效应。在26和80 kbar之间观察到逐渐的结构变形，但在对应于绝缘体-金属转变的较高压力下没有结构变化。我们的结论是绝缘体-金属过渡发生在没有任何扭曲的晶格-同构莫特过渡在一类新的二维材料，并在强烈对比的行为的其他MPX 3化合物。
The MPX3family of magnetic van-der-Waals materials (M denotes a first row transition metal and X either S or Se) are currently the subject of broad and intense attention for low-dimensional magnetism and transport and also for novel device and technological applications, but the vanadium compounds have until this point not been studied beyond their basic properties. We present the observation of an isostructural Mott insulator–metal transition in van-der-Waals honeycomb antiferromagnet V0.9PS3through high-pressure x-ray diffraction and transport measurements. We observe insulating variable-range-hopping type resistivity in V0.9PS3, with a gradual increase in effective dimensionality with increasing pressure, followed by a transition to a metallic resistivity temperature dependence between 112 and 124 kbar. The metallic state additionally shows a low-temperature upturn we tentatively attribute to the Kondo effect. A gradual structural distortion is seen between 26 and 80 kbar, but no structural change at higher pressures corresponding to the insulator–metal transition. We conclude that the insulator–metal transition occurs in the absence of any distortions to the lattice—an isostructural Mott transition in a new class of two-dimensional material, and in strong contrast to the behavior of the other MPX3compounds.