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arXiv 2309.04477cond-mat.mtrl-scicond-mat.str-el
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磁性范德华分子骨架Ni(NCS)$_2$的高压行为

High pressure behaviour of the magnetic van der Waals molecular framework Ni(NCS)$_2$

Madeleine Geers, David M. Jarvis, Cheng Liu, Siddharth S. Saxena, Jem Pitcairn, Emily Myatt, Sebastian A. Hallweger, Silva M. Kronawitter, Gregor Kieslich, Sanl… 展开作者

Madeleine Geers, David M. Jarvis, Cheng Liu, Siddharth S. Saxena, Jem Pitcairn, Emily Myatt, Sebastian A. Hallweger, Silva M. Kronawitter, Gregor Kieslich, Sanliang Ling, Andrew B. Cairns, Dominik Daisenberger, Oscar Fabelo, Laura Cañadillas-Delgado, Matthew J. Cliffe

AI总结:

本研究探究了二维范德华分子骨架反铁磁体Ni(NCS)$_2$在8.4 kbar压力下的结构与磁学特性,发现其可压缩性高、磁响应灵敏,为压力开关器件候选材料研发提供了新方向。

摘要:

二维材料具备一系列独特的磁学、电学和力学特性,可通过外部刺激进行调控。压力是一种尤为重要的刺激手段,它不仅易于实现,还能引发显著的物性响应,在低维材料中表现尤为突出。本文探究了最高8.4 kbar压力下,具有铁磁层的二维范德华(vdW)分子骨架反铁磁体Ni(NCS)$_2$的结构与磁学性质的压力依赖关系。\n通过X射线衍射与中子衍射的联合分析,我们发现Ni(NCS)$_2$的可压缩性显著高于同类范德华金属卤化物,且其压缩响应不仅在面外方向具有各向异性,在层内同样表现出各向异性。结合体磁化率与中子衍射数据,我们证实常压下的层状反铁磁相在研究的最高压力范围内保持稳定,但奈尔温度$T_\mathrm{N}$出现升高($ΔT_\mathrm{N} / T_\mathrm{N} = +19$ %),且具有较高的压力灵敏度($Q = \frac{1}{T_\mathrm{N}} \frac{\mathrm{d}T_\mathrm{N}}{\mathrm{d}P} = +2.3$ % kbar$^{-1}$),该数值在范德华材料的磁压力响应系数中处于较高水平。密度泛函理论计算表明,这一现象源于材料三维性的增强。\n这些结果为理解分子骨架型范德华磁体的压力响应提供了首批关键见解,同时表明对其他分子骨架型范德华磁体的研究有望发掘出适用于未来压力开关器件的候选材料。

英文摘要:

Two-dimensional materials offer a unique range of magnetic, electronic and mechanical properties which can be controlled by external stimuli. Pressure is a particularly important stimulus, as it can be achieved readily and can produce large responses, especially in low-dimensional materials. In this paper we explore the pressure-dependence of the structural and magnetic properties of a two-dimensional van der Waals (vdW) molecular framework antiferromagnet with ferromagnetic layers, Ni(NCS)$_2$, up to 8.4 kbar. Through a combination of X-ray and neutron diffraction analysis, we find that Ni(NCS)$_2$ is significantly more compressible than comparable vdW metal halides, and its response is anisotropic not only out of the plane, but also within the layers. Using bulk magnetisation and neutron diffraction data, we show that the ambient layered antiferromagnetic phase is maintained up to the largest investigated pressure, but with an enhanced Néel temperature, $T_\mathrm{N}$, ($ΔT_\mathrm{N} / T_\mathrm{N} = +19$ %) and a large pressure sensitivity ($Q = \frac{1}{T_\mathrm{N}} \frac{\mathrm{d}T_\mathrm{N}}{\mathrm{d}P} = +2.3$ % kbar$^{-1}$), one of the larger values of magnetic pressure responsiveness for a vdW material. Density functional theory calculations suggest that this is due to increasing three-dimensionality. These results provide some of the first insights into the pressure response of molecular framework vdW magnets and suggest investigation of other molecular framework vdW magnets might uncover contenders for future pressure-switchable devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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