Department of Materials, Imperial College London, Prince Consort Road, London, SW7 2BP, UK.
Micron. 2012 Feb;43(2-3):450-5. doi: 10.1016/j.micron.2011.10.026. Epub 2011 Nov 4.
In many cases, the key to obtaining good TEM results is in the sample preparation itself. Even once a thin specimen is achieved, other factors determine how well the sample will behave in the microscope. One of the main hindrances to TEM and STEM-EELS analysis is the build up of carbon contamination on the sample under the electron beam. This process may occur due to the nature of the sample itself or the support grids or films on which the sample sits. Here, we investigate contamination on holey and lacey carbon films from three different suppliers. We find that all grids have a large amount of mobile hydrocarbon contamination on them, as well as other larger contaminant species on the surface. Even after a variety of cleaning routines, none of the films are clean enough for STEM-EELS experiments requiring long acquisition times.
在许多情况下，获得良好的 TEM 结果的关键在于样品制备本身。即使获得了薄的样本，其他因素也决定了样本在显微镜下的表现如何。TEM 和 STEM-EELS 分析的主要障碍之一是电子束下样品上的碳污染的积累。这个过程可能是由于样品本身的性质，或者是样品所在的支撑网格或薄膜引起的。在这里，我们研究了来自三个不同供应商的有孔和花边碳膜上的污染。我们发现，所有的网格上都有大量的可移动碳氢化合物污染，表面上还有其他较大的污染物。即使经过各种清洗程序，也没有一个薄膜干净到足以进行需要长时间采集的 STEM-EELS 实验。
