原位/外场作用下原子尺度的纳米力学与结构演变研究

Study on Atom-Scale Nanomechanics and Structure under In-Situ/Application Field

综述了最近自主发展起来的一种原位/外场作用下纳米线力学性能与结构演变之间关系的原子分辨研究方法。该方法突破了通常将原子力显微镜集成到透射电镜中后,无法施加样品台双轴倾转,从而失去对研究对象进行原子分辨能力观察的技术瓶颈,发展了一套在透射电镜样品支撑网上施加外力载荷的技术,成功实现对SiC和Si纳米线脆/韧转变和超常塑性行为的原子分辨动态原位观察,为外场作用下单体一维纳米线力学性能和结构演变间关系的研究,提供了一种新的有效方法。

Newly - developed methods of in - situ atomic resolution observation of nanowires under bending or tensile strain conducted in a transmission electron microscope have been reviewed. This paper provided a comprehensive review on the methodological development and technical applications of in - situ microscopy, for investigating the structure - me- chanical - property relationship of a single one - dimensional nanowire. Details are presented on the direct imaging of brit- tle to ductile transition and plastic to superplastie behavior of semiconductor nanowires at atomic resolution, providing quantitative information on the mechanical behavior of nanomaterials. The studies on the Si and SiC nanowires clearly dem- onstrated their distinct, ＂unexpected＂ and superior plastic mechanical properties. Finally, a perspective is given on the future of nanomechanics.