title: Quantitative annular dark-field imaging of single-layer graphene.
abstract: A quantification procedure for annular dark-field (ADF) imaging, in which a quantitative contrast is given as a scattering intensity normalized by an incident probe current, is presented. The obtained ADF images are converted to quantitative ADF images using an empirical equation, which is a function of an ADF imaging system setting. The quantification procedure fully implements the nonlinear response of the ADF imaging system, which is critical in high-sensitivity observation. We applied the procedure for observation of a graphene specimen with 1-4 layers. The inner and outer angles of an ADF detector, which are important parameters in quantitative analyses, were precisely measured. The quantitative contrast of ADF images was in agreement with that of simulated images, and the quantitative ADF imaging allowed us to directly count the number of graphene layers.
authors: Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan yamashita.shunsuke@nims.go.jp kimoto.koji@nims.go.jp.
authors: Shunsuke
authors: S
authors: Yamashita
authors: Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors: Shogo
authors: S
authors: Koshiya
authors: Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan HREM Research Inc., 14-48 Matsukazedai, Higashimatsuyama, Saitama 355-0055, Japan.
authors: Kazuo
authors: K
authors: Ishizuka
authors: Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan yamashita.shunsuke@nims.go.jp kimoto.koji@nims.go.jp.
authors: Koji
authors: K
authors: Kimoto
mesh_terms: D006108:Graphite / Q000032:analysis*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D017348:Microscopy, Electron, Scanning Transmission / Q000379:methods*
chemical_list: D006108:Graphite
keywords: annular dark-field imaging; graphene; image simulation; quantitative analysis; scanning transmission electron microscopy