The Imaging of Individual Atoms

摘要

+Knowledge of the relative positions of atoms is crucial in many areas of physical and biological science. Indeed, many scientists create atomic images without realizing it. An undergraduate student, for example, wrestling with the infrared spectrum of a symmetric top molecule such as CH_3Br is actually constructing an image of the atoms. This is essentially atomic imaging, although by very indirect means. More desirable are direct imaging techniques, which avoid some of the pitfalls of modeling andcomputation. On page 413 of this issue, Nellist and Pennycook present a state-of-the-art example of direct imaging: atoms on supported catalysts at high resolution (1).