Xu Ke, Deng Shichen, Liang Ting, Cao Xuezheng, Han Meng, Zeng Xiaoliang, Zhang Zhisen, Yang Nuo, Wu Jianyang
Department of Physics, Research Institute for Biomimetics and Soft Matter, Jiujiang Research Institute and Fujian Provincial Key Laboratory for Soft Functional Materials Research, Xiamen University, Xiamen 361005, PR China.
State Key Laboratory of Coal Combustion, and School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074 PR China.
Nanoscale. 2022 Feb 24;14(8):3078-3086. doi: 10.1039/d1nr08505k.
MoS nanowires are emerging as key building blocks for flexible devices and are competitive with carbon nanotubes due to easier separation and functionalization. Here, it is reported the phonon thermal conductivity () of MoS nanowires molecular dynamics simulations. It shows a large tunability of low-frequency phonon thermal conductivity ()Amax from 27.2-191 W (m K), an increase of around 702% mechanical strain. Below critical tension/torsion strain, their phonon thermal conductivity monotonically reduces/enlarges; whereas above this value, an inverse trend is identified. On the other hand, MoS nanowires show unusual auxetic behavior. The transitions involved in phonon thermal conductivity are molecularly illustrated by a strain-induced crossover in bond configurations and are explained based on a competition mechanism between phonon scattering and group velocity. This study provides insights into the thermal transport and auxetic properties of low-dimensional structures and the thermal management of MoS nanowire-based systems.
二硫化钼纳米线正成为柔性器件的关键构建块，并且由于更容易分离和功能化，与碳纳米管相比具有竞争力。在此，通过分子动力学模拟报道了二硫化钼纳米线的声子热导率（）。它显示出低频声子热导率（）最大值从27.2 - 191 W/（m·K）具有很大的可调性，在机械应变作用下增加了约702%。在临界拉伸/扭转应变以下，它们的声子热导率单调降低/增大；而高于此值时，则出现相反趋势。另一方面，二硫化钼纳米线表现出不寻常的负泊松比行为。声子热导率所涉及的转变通过键构型中应变诱导的交叉从分子层面进行了说明，并基于声子散射和群速度之间的竞争机制进行了解释。这项研究为低维结构的热输运和负泊松比特性以及基于二硫化钼纳米线的系统的热管理提供了见解。
