Direct space high-resolution phase-contrast transmission electron microscopy (HRTEM) and atomic resolution Z-contrast scanning TEM (Z-STEM), when combined with tools for image-based nanocrystallography possess the capacity to derive the crystallographic phase and shape of nanocrystals. This paper introduces two such tools, (i) fringe fingerprinting in two dimensions for the identification of unknown nanocrystal phases and (ii) tilt protocol applications in three dimensions for the determination of the shape of nanocrystals. Although feasible in contemporary HRTEMs and Z-STEMs, image-based nanocrystallography will become much more viable with the increased availability of aberration-corrected transmission electron microscopes.
Both the Crystallography Open Database (COD)  and the Nano-Crystallography Database (NCD)  are discussed because the whole fingerprinting concept is only viable if there are comprehensive databases to support the identification of an unknown nanocrystal phase. While the COD contains the atomic coordinates and other crystallographic information for more than 20,000 crystal structures, the NCD, provides, in addition, interactive 3D visualizations and theoretical 2D fringe fingerprint plots of many of the crystal structures that are contained in the COD.
 Leslie M. (editor), Science 310 (2005) 597; http://crystallography.net
 Moeck P. et al., Mat. Res. Soc. Symp. Proc. 909E (2005), PP3.5, http://nanocrystallography.research.pdx.edu
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: May 7, 2006
Pages: 741 - 744
Industry sector: Advanced Materials & Manufacturing
Topics: Materials Characterization & Imaging