Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Krakow, Poland.
Department of Physics, SUPA, University of Strathclyde, Glasgow, U.K.
J Microsc. 2020 Feb;277(2):79-92. doi: 10.1111/jmi.12870.
We present a comparison of the precision of different approaches for orientation imaging using electron backscatter diffraction (EBSD) in the scanning electron microscope. We have used EBSD to image the internal structure of WC grains, which contain features due to dislocations and subgrains. We compare the conventional, Hough-transform based orientation results from the EBSD system software with results of a high-precision orientation refinement using simulated pattern matching at the full available detector resolution of 640 × 480 pixels. Electron channelling contrast imaging (ECCI) is used to verify the correspondence of qualitative ECCI features with the quantitative orientation data from pattern matching. For the investigated sample, this leads to an estimated pattern matching sensitivity of about 0.5 mrad (0.03°) and a spatial feature resolution of about 100 nm. In order to investigate the alternative approach of postprocessing noisy orientation data, we analyse the effects of two different types of orientation filters. Using reference features in the high-precision pattern matching results for comparison, we find that denoising of orientation data can reduce the spatial resolution, and can lead to the creation of orientation artefacts for crystallographic features near the spatial and orientational resolution limits of EBSD.
我们比较了在扫描电子显微镜中使用电子背散射衍射（EBSD）进行取向成像的不同方法的精度。我们已经使用 EBSD 来成像 WC 晶粒的内部结构，其中包含由于位错和亚晶粒引起的特征。我们将 EBSD 系统软件中基于霍夫变换的常规取向结果与使用模拟图案匹配在全分辨率为 640×480 像素的情况下进行高精度取向细化的结果进行了比较。电子通道对比度成像（ECCI）用于验证定性 ECCI 特征与图案匹配的定量取向数据之间的对应关系。对于所研究的样品，这导致了大约 0.5 mrad（0.03°）的图案匹配灵敏度和约 100nm 的空间特征分辨率。为了研究后处理噪声取向数据的替代方法，我们分析了两种不同类型的取向滤波器的影响。使用高精度图案匹配结果中的参考特征进行比较，我们发现，取向数据的去噪可以降低空间分辨率，并可能导致在 EBSD 的空间和取向分辨率极限附近的晶体特征产生取向伪影。
