论文标题
对ADF-STEM中位错的图像对比的见解
Insights into image contrast from dislocations in ADF-STEM
论文作者
论文摘要
竞争机制导致图像对比度的对比度来自环形暗场扫描透射电子显微镜ADF茎中的脱位。因此，对ADF茎对比的机制的明确理论理解对于正确解释错位图像至关重要。本文报告了对ADF茎的系统研究，这些ADF茎的对比是通过实验和计算的GAN标本中的位错的对比。边缘字符错位的系统实验ADF茎图像显示了许多特征对比特征，这些特征既取决于角度检测范围和样品中位错的特定位置。提出了基于电子通道和Bloch波散射理论的理论模型，并提出了使用Grillo S菌株通道方程的多层模拟支持的，以阐明这种复杂的对比现象的物理起源。
Competitive mechanisms contribute to image contrast from dislocations in annular dark field scanning transmission electron microscopy ADF STEM. A clear theoretical understanding of the mechanisms underlying the ADF STEM contrast is therefore essential for correct interpretation of dislocation images. This paper reports on a systematic study of the ADF STEM contrast from dislocations in a GaN specimen, both experimentally and computationally. Systematic experimental ADF STEM images of the edge character dislocations revealed a number of characteristic contrast features that are shown to depend on both the angular detection range and specific position of the dislocation in the sample. A theoretical model based on electron channelling and Bloch wave scattering theories, supported by multislice simulations using Grillo s strain channelling equation, is proposed to elucidate the physical origin of such complex contrast phenomena.
