Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan.
ACS Nano. 2013 Jun 25;7(6):4700-7. doi: 10.1021/nn4023558. Epub 2013 Jun 12.
With innovative modern material-growth methods, a broad spectrum of fascinating materials with reduced dimensions-ranging from single-atom catalysts, nanoplasmonic and nanophotonic materials to two-dimensional heterostructural interfaces-is continually emerging and extending the new frontiers of materials research. A persistent central challenge in this grand scientific context has been the detailed characterization of the individual objects in these materials with the highest spatial resolution, a problem prompting the need for experimental techniques that integrate both microscopic and spectroscopic capabilities. To date, several representative microscopy-spectroscopy combinations have become available, such as scanning tunneling microscopy, tip-enhanced scanning optical microscopy, atom probe tomography, scanning transmission X-ray microscopy, and scanning transmission electron microscopy (STEM). Among these tools, STEM boasts unique chemical and electronic sensitivity at unparalleled resolution. In this Perspective, we elucidate the advances in STEM and chemical mapping applications at the atomic scale by energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy with a focus on the ultimate challenge of chemical quantification with atomic accuracy.
利用创新的现代材料生长方法，不断涌现出具有降低维度的各种迷人材料，范围从单原子催化剂、纳米等离子体和纳米光子材料到二维异质结构界面，这些材料扩展了材料研究的新前沿。在这个宏伟的科学背景下，一个持续的核心挑战一直是用最高空间分辨率对这些材料中的各个物体进行详细的特征描述，这个问题促使人们需要将微观和光谱学功能结合起来的实验技术。迄今为止，已经有几种具有代表性的显微镜-光谱学组合可供使用，例如扫描隧道显微镜、尖端增强扫描光学显微镜、原子探针断层扫描、扫描透射 X 射线显微镜和扫描透射电子显微镜（STEM）。在这些工具中，STEM 具有独特的化学和电子灵敏度，分辨率无与伦比。在本文观点中，我们通过能量色散 X 射线光谱和电子能量损失光谱阐明了在原子尺度上 STEM 和化学映射应用的进展，重点介绍了用原子精度进行化学定量的最终挑战。
