Li Lili, Yang Jie
School of Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia.
Sci Rep. 2018 Feb 19;8(1):3227. doi: 10.1038/s41598-018-21633-1.
This paper investigates the mechanical behaviors of few-layer black phosphorus (FLBP) by using molecular dynamics simulations. Results show that both tensile and compressive behaviors are strongly anisotropic in the armchair and zigzag directions due to the unidirectional puckers in each atomic layer, and that the compressive behavior is dependent on the number of atomic layers. In particular, the compressive and buckling strengths of FLBP can be significantly enhanced by stacking more atomic layers together, while this has little influence on both Young's modulus and tensile strength. It is interesting to found that increasing the number of atomic layers in FLBP or the dimension ratio can lead to a drastically reduced flexibility in armchair direction, showing that both compressive and buckling strengths become higher than those in zigzag direction. It is also demonstrated that the reorientation of FLBP's atomic configuration occurs under certain conditions. The mechanism of deformation underlying the mechanical behaviors of FLBP is also discussed, suggesting that changing the number of atomic layers is an effective way to engineer two-dimensional materials for desired material properties.
本文通过分子动力学模拟研究了少层黑磷（FLBP）的力学行为。结果表明，由于每个原子层中存在单向褶皱，拉伸和压缩行为在扶手椅方向和锯齿方向上均表现出强烈的各向异性，并且压缩行为取决于原子层数。特别地，通过将更多原子层堆叠在一起，可以显著提高FLBP的压缩强度和屈曲强度，而这对杨氏模量和拉伸强度的影响很小。有趣的是，发现增加FLBP中的原子层数或尺寸比会导致扶手椅方向的柔韧性急剧降低，这表明压缩强度和屈曲强度均高于锯齿方向。还证明了FLBP的原子构型在一定条件下会发生重新取向。本文还讨论了FLBP力学行为背后的变形机制，表明改变原子层数是设计具有所需材料性能的二维材料的有效方法。
