Pennycook S J, Chisholm M F, Lupini A R, Varela M, Borisevich A Y, Oxley M P, Luo W D, van Benthem K, Oh S-H, Sales D L, Molina S I, García-Barriocanal J, Leon C, Santamaría J, Rashkeev S N, Pantelides S T
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
Philos Trans A Math Phys Eng Sci. 2009 Sep 28;367(1903):3709-33. doi: 10.1098/rsta.2009.0112.
The new possibilities of aberration-corrected scanning transmission electron microscopy (STEM) extend far beyond the factor of 2 or more in lateral resolution that was the original motivation. The smaller probe also gives enhanced single atom sensitivity, both for imaging and for spectroscopy, enabling light elements to be detected in a Z-contrast image and giving much improved phase contrast imaging using the bright field detector with pixel-by-pixel correlation with the Z-contrast image. Furthermore, the increased probe-forming aperture brings significant depth sensitivity and the possibility of optical sectioning to extract information in three dimensions. This paper reviews these recent advances with reference to several applications of relevance to energy, the origin of the low-temperature catalytic activity of nanophase Au, the nucleation and growth of semiconducting nanowires, and the origin of the eight orders of magnitude increased ionic conductivity in oxide superlattices. Possible future directions of aberration-corrected STEM for solving energy problems are outlined.
像差校正扫描透射电子显微镜（STEM）的新可能性远远超出了横向分辨率提高2倍或更多这一最初动机。更小的探针还提高了单原子灵敏度，无论是成像还是光谱分析，使得在Z衬度图像中能够检测到轻元素，并利用明场探测器与Z衬度图像逐像素关联实现大幅改进的相衬度成像。此外，增加的探针形成孔径带来了显著的深度灵敏度以及光学切片的可能性，以便在三维空间中提取信息。本文结合与能源相关的几个应用，包括纳米相金低温催化活性的起源、半导体纳米线的成核与生长以及氧化物超晶格中离子电导率提高八个数量级的起源，综述了这些最新进展。还概述了像差校正STEM在解决能源问题方面可能的未来发展方向。
