论文标题
工程缺陷以调节单层MOS2的断裂强度:原子研究
Engineered Defects to Modulate Fracture Strength of Single Layer MoS2: An Atomistic Study
论文作者
论文摘要
我们使用经典的分子动力学(MD)模拟来研究预折叠的纳米孔单层MOS2(SLMOS2)的机械性能以及裂缝和孔之间相互作用的影响。我们发现,预裂和纳米孔SLMOS2的失败以脆性型断裂为主。与曲折方向相比,扶手椅方向的键表现出对裂纹传播的抗性。我们将Griffith预测的脆弱失败与MD断裂强度和韧性进行了比较,并发现了实质性差异,这些差异限制了Griffith Criterion在纳米裂缝和毛孔的情况下适用于SLMOS2。接下来,我们证明可以通过对称放置的毛孔来增强预裂SLMOS2的机械性能,并在中央裂缝周围进行辅助裂纹,并且可以优化此类排列的位置,以最大程度地增强强度的增强。这样的研究将有助于基于应变工程的SLMOS2和其他类似的过渡金属二分法的高级设计。
We use classical molecular dynamics (MD) simulations to investigate the mechanical properties of pre-cracked, nano-porous single layer MoS2 (SLMoS2) and the effect of interactions between cracks and pores. We found that the failure of pre-cracked and nano-porous SLMoS2 is dominated by brittle type fracture. Bonds in armchair direction show a stronger resistance to crack propagation compared to the zigzag direction. We compared the brittle failure of Griffith prediction with the MD fracture strength and toughness and found substantial differences that limit the applicability of Griffith criterion for SLMoS2 in case of nano-cracks and pores. Next, we demonstrate that the mechanical properties of pre-cracked SLMoS2 can be enhanced via symmetrically placed pores and auxiliary cracks around a central crack and position of such arrangements can be optimized for maximum enhancement of strengths. Such a study would help towards strain engineering based advanced designing of SLMoS2 and other similar Transition Metal Dichalcogenides.