Details

Autor(en) / Beteiligte

• Zhong, Zhichao
• Aveyard, Richard
• Rieger, Bernd
• Bals, Sara
• Palenstijn, Willem Jan
• Batenburg, K. Joost

Titel

Automatic correction of nonlinear damping effects in HAADF–STEM tomography for nanomaterials of discrete compositions

Ist Teil von

• Ultramicroscopy, 2018-01, Vol.184 (Pt B), p.57-65

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •An algorithm is proposed to correct cupping artifacts in HAADF–STEM tomography.•It is an automated algorithm that requires no extra measurement.•The algorithm is applied on different hetero nanostructures. HAADF-STEM tomography is a common technique for characterizing the three-dimensional morphology of nanomaterials. In conventional tomographic reconstruction algorithms, the image intensity is assumed to be a linear projection of a physical property of the specimen. However, this assumption of linearity is not completely valid due to the nonlinear damping of signal intensities. The nonlinear damping effects increase w.r.t the specimen thickness and lead to so-called “cupping artifacts”, due to a mismatch with the linear model used in the reconstruction algorithm. Moreover, nonlinear damping effects can strongly limit the applicability of advanced reconstruction approaches such as Total Variation Minimization and discrete tomography. In this paper, we propose an algorithm for automatically correcting the nonlinear effects and the subsequent cupping artifacts. It is applicable to samples in which chemical compositions can be segmented based on image gray levels. The correction is realized by iteratively estimating the nonlinear relationship between projection intensity and sample thickness, based on which the projections are linearized. The correction and reconstruction algorithms are tested on simulated and experimental data.