Effect of convergent beam semiangle on image intensity in HAADF STEM images.
In this study, we experimentally and theoretically show that the intensities of bright spots in a spherical aberration (C(s))-uncorrected high-angle annular dark-field (HAADF) scanning transmission electron microscope (STEM) image of [011]-oriented Co(3)O(4), which has two different numbers of Co atoms in the projected atomic columns, are reversed with increasing sample thickness. However, C(s)-corrected HAADF STEM images produce intensities that correctly depend on the average number of atoms in the projected atomic columns. From an analysis based on the Bloch-wave theorem, it is found that an insufficient semiangle of the incident convergent beam yields intensities that do not depend on the average atomic number in the atomic columns.
Kuramochi
Koji
K
Department of Physics, Tokyo University of Science, Tokyo 162-8601, Japan.
Kotaka
Yasutoshi
Y
Yamazaki
Takashi
T
Ohtsuka
Masahiro
M
Hashimoto
Iwao
I
Watanabe
Kazuto
K