STEM beam channeling in BaSnO3/LaAlO3 perovskite bilayers and visualization of 2D misfit dislocation network

Hwanhui Yun; Abhinav Prakash; Bharat Jalan; Jong Seok Jeong; K Andre Mkhoyan

doi:10.1016/j.ultramic.2019.112863

STEM beam channeling in BaSnO₃/LaAlO₃ perovskite bilayers and visualization of 2D misfit dislocation network

Ultramicroscopy. 2020 Jan:208:112863. doi: 10.1016/j.ultramic.2019.112863. Epub 2019 Oct 24.

Authors

Hwanhui Yun¹, Abhinav Prakash², Bharat Jalan², Jong Seok Jeong³, K Andre Mkhoyan⁴

Affiliations

¹ Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address: [email protected].
² Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
³ Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA; Analytical Sciences Center, LG Chem Ltd., Daejeon, Republic of Korea. Electronic address: [email protected].
⁴ Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address: [email protected].

PMID: 31683082
DOI: 10.1016/j.ultramic.2019.112863

Abstract

A study of the STEM probe channeling in a heterostructured crystalline bilayer specimens is presented here with a goal to guide STEM-based characterization of multilayer structures. STEM analysis of perovskite BaSnO₃/LaAlO₃ bilayers is performed and the dominating effects of beam channeling on HAADF- and LAADF-STEM are illustrated. To study the electron beam channeling through BaSnO₃/LaAlO₃ bilayers, probe intensity depth profiles are calculated, and the effects of probe defocus and atomic column alignment are discussed. Characteristics of the beam channeling are correlated to resulting ADF-STEM images, which is then tested by comparing focal series of plan-view HAADF-STEM images to those recorded experimentally. Additionally, discussions on how to visualize the misfit dislocation network at the BaSnO₃/LaAlO₃ interface using HAADF- and LAADF-STEM images are provided.

Keywords: BaSnO(3); Channeling; Focal series; HAADF; Heterostructure; LAADF; LaAlO(3); Multislice; STEM.