Aberration-corrected scanning transmission electron microscopy: The potential for nano- and interface science

The sub-Ångström probe of an aberration-corrected scanning transmission electron microscope will enable imaging and analysis of nanostructures and interfaces with unprecedented resolution and sensitivity. In conjunction with first-principles theory, new insights are anticipated into the atomistic processes of growth and the subtle link between structure and functionality. We present initial results from the aberration-corrected microscopes at Oak Ridge National Laboratory that indicate the kinds of studies that will become feasible in the near future. Examples include (1) the three-dimensional location and identification of individual dopant and impurity atoms in semiconductor interfaces, and their effect on local electronic structure; (2) the accurate reconstruction of surface atomic and electronic structure on nanocrystals, and the effect on optical properties; and (3) the ability to distinguish which configurations of catalyst atoms are active, and why.