论文标题
克服厚材料的聚焦探针Ptychography中的对比反转：有效确定材料科学中局部原子结构的最佳管道
Overcoming contrast reversals in focused probe ptychography of thick materials: an optimal pipeline for efficiently determining local atomic structure in materials science
论文作者
论文摘要
PtyChography在扫描透射电子显微镜（STEM）中提供了高效的成像，但是问题仍然存在于其对强散射样品的适用性，例如最常见的材料Science。尽管随着样品的预测电位的增加，对比度逆转可能会出现在Ptychographic阶段图像中，但我们在这里显示如何通过少量的散焦很容易克服它们。散焦的量足够小，以至于使用环形暗场（ADF）信号聚焦时可以自然存在，但也可以调整后采集后。与其他茎技术相比，强烈散射材料的Ptychographic图像更清晰，并且可以更好地揭示重晶格中的轻质原子柱。此外，现在可以通过最快的ADF扫描同时收集Ptychography的数据。这种敏感性和解释性的结合为材料科学提供了理想的工作流程。
Ptychography provides highly efficient imaging in scanning transmission electron microscopy (STEM), but questions have remained over its applicability to strongly scattering samples such as those most commonly seen in materialsscience. Although contrast reversals can appear in ptychographic phase images as the projected potentials of the sample increase, we show here how these can be easily overcome by a small amount of defocus. The amount of defocus is small enough that it can exist naturally when focusing using the annular dark field (ADF) signal, but can also be adjusted post acquisition. The ptychographic images of strongly scattering materials are clearer at finite doses than other STEM techniques, and can better reveal light atomic columns within heavy lattices. In addition data for ptychography can now be collected simultaneously with the fastest of ADF scans. This combination of sensitivity and interpretability presents an ideal workflow for materials science.
