S. Van Aert et D. Van Dyck, Do smaller probes in a scanning transmission electron microscope result inmore precise measurement of the distances between atom columns?, PHIL MAG B, 81(11), 2001, pp. 1833-1846
Conventionally, the design of annular dark-field (ADF) scanning transmissio
n electron microscopy (STEM) experiments is mostly based on resolution crit
eria related to direct visual interpretability. However, the future of imag
e interpretation lies in quantitative structure determination. Since this i
s a different purpose, the design has to be reconsidered. In this paper, a
precision-based performance measure is proposed, which follows from a simpl
ified model. From this, the optimal experimental design for a quantitative
ADF STEM experiment is derived. The outcome of this optimization is that th
e probe should not be as small as possible, but that the optimal width depe
nds strongly on the material under investigation. Furthermore, it turns out
that the radius of the hole in the detector should be as large as the opti
mal aperture radius.