Local crystal structure analysis with 10-pm accuracy using scanning transmission electron microscopy

Abstract

We demonstrate local crystal structure analysis based on annular dark-field (ADF) imaging in scanning transmission electron microscopy (STEM). Using a stabilized STEM instrument and customized software, we first realize high accuracy of elemental discrimination and atom-position determination with a 10-pm-order accuracy, which can reveal major cation displacements associated with a variety of material properties, e.g. ferroelectricity and colossal magnetoresistivity. A-site ordered/disordered perovskite manganites Tb(0.5)Ba(0.5)MnO(3) are analysed; A-site ordering and a Mn-site displacement of 12 pm are detected in each specific atomic column. This method can be applied to practical and advanced materials, e.g. strongly correlated electron materials.

Atomic level observation of octahedral distortions at the perovskite oxide heterointerface

“…4.2 μs/pixel). Then, the multiple images were superimposed after correcting for the relative drifts26. This procedure provides high resolution STEM images with improved signal-to-noise (SN) ratio and with minimized image distortion.…”

“…The images acquired with STEM, however, were difficult to use for precise structural analysis because of image distortions due to drifts of both the specimen and incident probe. In order to overcome this problem and obtain structural images with minimized image distortion, we used the fast multiple-image acquisition and drift correction techniques using cross correlation of the image26. In addition, we were able to precisely determine the atomic positions using Bragg filtering and cubic interpolation techniques2728.…”

Research Update: Interface-engineered oxygen octahedral tilts in perovskite oxide heterostructures

“…[14][15][16][17][18][19][20][21] The recent development of annular bright-field (ABF) imaging in STEM allows for simultaneous mapping of both light and heavy elements [22][23][24] and makes it possible to visualize oxygen coordination environments in the heterostructures. 18,25,26 Fast multiple-image acquisition and drift correction techniques using a cross correlation of the images 27 have been also demonstrated to minimize the image distortions due to drifts in both the specimen and incident probe in STEM, and consequently, the atomic positions for all constituent atoms-including oxygen-can be determined with sub-Ångström precision. 18,19,28 In this article, we present our investigations of oxygen octahedral distortions in heterostructures consisting of perovskite oxides SrRuO 3 (SRO) and BaTiO 3 (BTO) grown on GdScO 3 (GSO) substrates and our investigations of their influences on the magneto-transport properties of the SRO layer.…”

Metastable ultrathin crystal in thermally grown SiO2 film on Si substrate

“…18 In this study, we recorded a large number of STEM images as a time series using software developed by the authors. [20][21][22] The time-series STEM images allowed us to investigate the stability of the atomic arrangement against the electron dose. A STEM image simulation was performed using a multislice program (HREM Research Inc., xHREM and STEM extension) using a supercell that includes 92,000 atoms.…”