Accurate Nanoscale Crystallography in Real-Space Using Scanning Transmission Electron Microscopy

• Published in: Microscopy and microanalysis Vol. 21; no. 4; pp. 946 - 952
• Main Authors: Dycus, J. Houston, Harris, Joshua S., Sang, Xiahan, Fancher, Chris M., Findlay, Scott D., Oni, Adedapo A., Chan, Tsung-ta E., Koch, Carl C., Jones, Jacob L., Allen, Leslie J., Irving, Douglas L., LeBeau, James M.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.08.2015; Oxford University Press; Microscopy Society of America (MSA)
• Subjects: Accuracy; Alloys; Calibration; Crystal structure; Crystallography; Materials Applications and Techniques; Software; Transmission electron microscopy; X-rays; Bi2Te3; scanning transmission electron microscopy; atomic resolution spectroscopy; nanoscale metrology
• ISSN: 1431-9276; 1435-8115
• DOI: 10.1017/S1431927615013732

Here, we report reproducible and accurate measurement of crystallographic parameters using scanning transmission electron microscopy. This is made possible by removing drift and residual scan distortion. We demonstrate real-space lattice parameter measurements with <0.1% error for complex-layered chalcogenides Bi2Te3, Bi2Se3, and a Bi2Te2.7Se0.3 nanostructured alloy. Pairing the technique with atomic resolution spectroscopy, we connect local structure with chemistry and bonding. Combining these results with density functional theory, we show that the incorporation of Se into Bi2Te3 causes charge redistribution that anomalously increases the van der Waals gap between building blocks of the layered structure. The results show that atomic resolution imaging with electrons can accurately and robustly quantify crystallography at the nanoscale.