Structurally Driven Environmental Degradation of Friction in MoS2 Films
Structurally Driven Environmental Degradation of Friction in MoS2 Films
复制标题
二硫化钼薄膜摩擦的结构驱动环境退化
DOI：
10.1007/s11249-021-01453-7
复制
发表时间：
2021-09-01
影响因子：
3.2
通讯作者：
Chandross, Michael
中科院分区：
文献类型：
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作者：
Curry, John F.;Ohta, Taisuke;Chandross, Michael
我们报告了在不同的环境和接触条件下，使用各种计算和实验技术研究二硫化钼薄膜的摩擦机制。采用分子动力学模拟方法研究了水和分子氧对二硫化钼片在初始滑动过程中摩擦键合的影响。通过光电子发射显微镜（PEEM）和开尔文探针力显微镜（KPFM）表征，确定了剪切改性材料在MoS2磨损痕顶部几纳米内的功函数变化。结果表明，功函数随接触条件和环境的变化而变化，并通过密度泛函理论（DFT）计算和文献报道表明，功函数与基取向表面层的片层尺寸和厚度相关。纳米尺度模拟和宏观尺度实验的结果表明，二硫化钼的摩擦行为的演变主要与基取向的分子薄表面膜的形成或抑制有关。
We report an investigation of the friction mechanisms of MoS2 thin films under changing environments and contact conditions using a variety of computational and experimental techniques. Molecular dynamics simulations were used to study the effects of water and molecular oxygen on friction and bonding of MoS2 lamellae during initial sliding. Characterization via photoelectron emission microscopy (PEEM) and Kelvin probe force microscopy (KPFM) were used to determine work function changes in shear modified material within the top few nanometers of MoS2 wear scars. The work function was shown to change with contact conditions and environment, and shown by density functional theory (DFT) calculations and literature reports to be correlated with lamellae size and thickness of the basally oriented surface layer. Results from nanoscale simulations and macroscale experiments suggest that the evolution of the friction behavior of MoS2 is linked primarily to the formation or inhibition of a basally oriented, molecularly thin surface film with long-range order.