Cretu Ovidiu, Lin Yung-Chang, Suenaga Kazutomo
National Institute of Advanced Industrial Science and Technology (AIST), Nanotube Research Center, Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
National Institute of Advanced Industrial Science and Technology (AIST), Nanotube Research Center, Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
Micron. 2015 May;72:21-7. doi: 10.1016/j.micron.2015.02.002. Epub 2015 Feb 19.
We present a study of the inelastic effects caused by electron irradiation in monolayer hexagonal boron nitride (h-BN). The data was obtained through in situ experiments performed inside a low-voltage aberration-corrected transmission electron microscope (TEM). By using various specialized sample holders, we study defect formation and evolution with sub-nanometer resolution over a wide range of temperatures, between -196 and 1200 °C, highlighting significant differences in the geometry of the structures that form. The data is then quantified, allowing insight into the defect formation mechanism, which is discussed in comparison with the potential candidate damage processes. We show that the defect shapes are determined by an interplay between electron damage, which we assign to charging, and thermal effects. We additionally show that this damage can be avoided altogether by overlapping the samples with a monolayer of graphene, confirming this for h-BN and providing a way to overcome the well-known fragility of h-BN under the electron beam.
我们展示了一项关于单层六方氮化硼（h-BN）中电子辐照引起的非弹性效应的研究。数据是通过在低压像差校正透射电子显微镜（TEM）内进行的原位实验获得的。通过使用各种专门的样品架，我们在-196至1200°C的宽温度范围内，以亚纳米分辨率研究缺陷的形成和演变，突出了所形成结构几何形状的显著差异。然后对数据进行量化，以便深入了解缺陷形成机制，并与潜在的候选损伤过程进行比较讨论。我们表明，缺陷形状由我们归因于充电的电子损伤和热效应之间的相互作用决定。我们还表明，通过将样品与单层石墨烯重叠，可以完全避免这种损伤，这在h-BN中得到了证实，并提供了一种克服h-BN在电子束下众所周知的易碎性的方法。
