title: Effect of convergent beam semiangle on image intensity in HAADF STEM images.
abstract: 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.
authors.affiliation: Department of Physics, Tokyo University of Science, Tokyo 162-8601, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kuramochi
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Kotaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohtsuka
authors.forename: Iwao
authors.initials: I
authors.lastname: Hashimoto
authors.forename: Kazuto
authors.initials: K
authors.lastname: Watanabe