title: Three dimensional analysis of the composition in solid alloys by variable probe in scanning transmission electron microscopy.
abstract: This paper reports on a novel approach to quantitatively reconstruct the column by column composition and the 3D distribution of guest atoms inside a host matrix by scanning transmission electron microscopy high angle annular dark field technique. We propose a new mathematical framework that allows to jointly analyze the information from a set of experiments with variable beam convergence and/or defocus. Our scheme allows to reconstruct the atomic distribution along the imaged columns from the measured intensity, for any dependence of the probe intensity on the depth. It is therefore well suited to incorporate channeling effects that are usually neglected in other approaches. As a case study, we focus here on the systematic variation of the beam convergence that permits to set the maximum of the channeling oscillations at different depths. We aim here to define the reliability and the limitation of this technique by the application of the method to accurate dynamic simulations in the case of the InGaN alloy.
authors.affiliation: IMEM-CNR, Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Rotunno
authors.affiliation: Leibniz Institute for Crystal Growth, Max-Born-Straße 2, 12489 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Albrecht
authors.affiliation: Leibniz Institute for Crystal Growth, Max-Born-Straße 2, 12489 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Markurt
authors.affiliation: Leibniz Institute for Crystal Growth, Max-Born-Straße 2, 12489 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Remmele
authors.affiliation: IMEM-CNR, Parco Area delle Scienze 37/A, 43124 Parma, Italy; S3, CNR-NANO, Via Campi 213/A, 41100 Modena, Italy. Electronic address: vincenzo.grillo@cnr.it.
authors.forename: V
authors.initials: V
authors.lastname: Grillo
keywords: 3D analysis; Channeling; Inversion methods; STEM-HAADF