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

Abstract

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.

Transmission electron microscopy analysis of some transition metal compounds for energy storage and conversion

“…This is in common with the results obtained by Dycus et al [113] in which it is determined that Se dopants in Bi 2 Te 3 preferentially occupy Te1 sites. …”

“…As shown in Fig. 5, the doped M A N U S C R I P T [113]. Although quintuple layer consisting five alternating Bi and Te(Se) atomic layers can be well resolved, the distribution of dopant atoms needs to be further clarified.…”

Precision controlled atomic resolution scanning transmission electron microscopy using spiral scan pathways

“…Therefore, post-acquisition scan distortion correction methods have been proposed based on analyzing features of the STEM images11121314151617. For example, by changing the scan direction for a series of images, the revolving STEM (RevSTEM) method can be used to efficiently measure drift vectors and correct drift distortions, enabling picometer-level measurements of the lattice constants18 and local displacements14. Similarly, non-linear drift distortion can be corrected from pairs of orthogonal scanned STEM images17.…”

Oxygen vacancy ordering induced displacements of cations in yttria-stabilized zirconia

“…[3][4][5][6] Using aberration corrected STEM, the lattice distortions in materials can now be measured on a unit-cell by a unit-cell basis and at the picometer level. [7][8][9] The clear view of atom positions enables direct comparison of experiment with theory modeling. 7,8,[10][11][12] In this work, we employ the contrast based on the high-angle scattering of electrons (Z-contrast) in a STEM mode to image the cation sub-lattice only, which allows for directly measuring vacancy-induced displacements of cations in YSZ.…”

“…[7][8][9] The clear view of atom positions enables direct comparison of experiment with theory modeling. 7,8,[10][11][12] In this work, we employ the contrast based on the high-angle scattering of electrons (Z-contrast) in a STEM mode to image the cation sub-lattice only, which allows for directly measuring vacancy-induced displacements of cations in YSZ. In conjunction with density-functional theory (DFT) calculations, we show that the location and concentration of oxygen vacancies in YSZ can be determined from the measured atomic displacements of the cation sub-lattice.…”