arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2409.07698cond-mat.mtrl-scicond-mat.mes-hall
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压力下二维层状纳米材料晶格动力学与弹性常数的层间工程

Interlayer Engineering of Lattice Dynamics and Elastic Constants of 2D Layered Nanomaterials under Pressure

Guoshuai Du, Lili Zhao, Shuchang Li, Jing Huang, Susu Fang, Wuxiao Han, Jiayin Li, Yubing Du, Jiaxin Ming, Tiansong Zhang, Jun Zhang, Jun Kang, Xiaoyan Li, Weigao Xu, Yabin Chen

AI总结:

该研究针对二维层状纳米材料层间势与弹性能难以准确量化的问题,采用基于超低频拉曼光谱的压力工程策略,结合理论模拟,揭示了不同厚度MoS₂拉曼模频移随压力变化的层数依赖规律,为相关材料应用提供了参考。

摘要:

二维(2D)层状纳米材料的层间耦合可为我们提供激发其优异性能的新策略,例如扭曲层的奇异平带与非常规超导性、莫尔激子的形成及相关非平凡拓扑结构。然而,尽管已付出大量努力,如何准确量化层间势并进一步测量二维材料的弹性能仍不明确。本文中,研究人员基于超低频拉曼光谱,通过压力工程策略系统研究了二维纳米材料的层数依赖晶格动力学与弹性常数。利用线性链模型分析了不同厚度MoS₂的剪切模与层呼吸拉曼位移。有趣的是,研究发现剪切模和呼吸拉曼模的层数依赖dω/dP呈现相反趋势,这与我们的分子动力学模拟和密度泛函理论计算结果定量一致。这些结果可推广到其他范德华体系,或可为二维材料在纳米力学和纳米电子学中的潜在应用提供启示。

英文摘要:

Interlayer coupling in two-dimensional (2D) layered nanomaterials can provide us novel strategies to evoke their superior properties, such as the exotic flat bands and unconventional superconductivity of twisted layers, the formation of moiré excitons and related nontrivial topology. However, to accurately quantify interlayer potential and further measure elastic properties of 2D materials remains vague, despite significant efforts. Herein, the layer-dependent lattice dynamics and elastic constants of 2D nanomaterials have been systematically investigated via pressure-engineering strategy based on ultralow frequency Raman spectroscopy. The shearing mode and layer-breathing Raman shifts of MoS2 with various thicknesses were analyzed by the linear chain model. Intriguingly, it was found that the layer-dependent dω/dP of shearing and breathing Raman modes display the opposite trends, quantitatively consistent with our molecular dynamics simulations and density functional theory calculations. These results can be generalized to other van der Waals systems, and may shed light on the potential applications of 2D materials in nanomechanics and nanoelectronics.

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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