Meyer J C, Kotakoski J, Mangler C
University of Vienna, Department of Physics, Vienna, Austria.
University of Vienna, Department of Physics, Vienna, Austria.
Ultramicroscopy. 2014 Oct;145(100):13-21. doi: 10.1016/j.ultramic.2013.11.010. Epub 2013 Dec 1.
Beam-induced structural modifications are a major nuisance in the study of materials by high-resolution electron microscopy. Here, we introduce a new approach to circumvent the radiation damage problem by a statistical treatment of large, noisy, low-dose data sets of non-periodic configurations (e.g. defects) in the material. We distribute the dose over a mixture of different defect structures at random positions and with random orientations, and recover representative model images via a maximum likelihood search. We demonstrate reconstructions from simulated images at such low doses that the location of individual entities is not possible. The approach may open a route to study currently inaccessible beam-sensitive configurations.
在通过高分辨率电子显微镜研究材料时,电子束诱导的结构变化是一个主要的干扰因素。在此,我们引入一种新方法,通过对材料中非周期性构型(如缺陷)的大量有噪声的低剂量数据集进行统计处理,来规避辐射损伤问题。我们将剂量分布在随机位置和随机取向的不同缺陷结构的混合体上,并通过最大似然搜索恢复代表性的模型图像。我们展示了在如此低剂量下从模拟图像进行的重建,以至于无法确定单个实体的位置。该方法可能为研究目前难以通过电子束研究的敏感构型开辟一条途径。