Attariani Hamed, Momeni Kasra, Adkins Kyle
Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435, United States.
Engineering Program, Wright State University - Lake Campus, Celina, Ohio 45822, United States.
ACS Omega. 2017 Feb 23;2(2):663-669. doi: 10.1021/acsomega.6b00500. eCollection 2017 Feb 28.
Moving to nanoscale is a path to get perfect materials with superior properties. Yet defects, such as stacking faults (SFs), are still forming during the synthesis of nanomaterials and, according to common notion, degrade the properties. Here, we demonstrate the possibility of engineering defects to, surprisingly, achieve mechanical properties beyond those of the corresponding perfect structures. We show that introducing SFs with high density increases the Young's Modulus and the critical stress under compressive loading of the nanowires above those of a perfect structure. The physics can be explained by the increase in intrinsic strain due to the presence of SFs and overlapping of the corresponding strain fields. We have used the molecular dynamics technique and considered ZnO as our model material due to its technological importance for a wide range of electromechanical applications. The results are consistent with recent experiments and propose a novel approach for the fabrication of stronger materials.
向纳米尺度发展是获得具有卓越性能的完美材料的途径。然而，诸如堆垛层错（SFs）之类的缺陷在纳米材料合成过程中仍然会形成，并且根据普遍观念，这些缺陷会降低材料性能。在此，我们证明了对缺陷进行工程设计的可能性，令人惊讶的是，这样做能够实现超越相应完美结构的机械性能。我们表明，引入高密度的堆垛层错会使纳米线在压缩载荷下的杨氏模量和临界应力高于完美结构的纳米线。其物理原理可以通过由于堆垛层错的存在以及相应应变场的重叠导致的本征应变增加来解释。由于氧化锌在广泛的机电应用中具有重要的技术价值，我们使用分子动力学技术并将其作为我们的模型材料。这些结果与最近的实验一致，并提出了一种制造更强材料的新方法。
