Imaging columns of the light elements carbon, nitrogen and oxygen with sub Ångstrom resolution

• Published in: Ultramicroscopy Vol. 89; no. 4; pp. 243 - 263
• Main Authors: Kisielowski, C., Hetherington, C.J.D., Wang, Y.C., Kilaas, R., O’Keefe, M.A., Thust, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-11-2001; Elsevier Science
• Subjects: Condensed matter: structure, mechanical and thermal properties; Electron, ion, and scanning probe microscopy; Electron, positron and ion microscopes, electron diffractometers and related techniques; Exact sciences and technology; Field emission- and field-ion microscopy; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Structure of solids and liquids; crystallography; 68.35.−p; 07.80; 001; 004; 61.16.−d; Semiconductor materials; Gallium nitrides; Diamonds; Binary compounds; Solid-solid interfaces; Experimental study; Field emission electron microscopy; Image reconstruction; Sapphire; Silicon; Crystal faces; Spatial resolution; Lattice image
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/S0304-3991(01)00090-0

It is reported that lattice imaging with a 300
kV field emission microscope in combination with numerical reconstruction procedures can be used to reach an interpretable resolution of about 80
pm for the first time. A retrieval of the electron exit wave from focal series allows for the resolution of single atomic columns of the light elements carbon, nitrogen, and oxygen at a projected nearest neighbor spacing down to 85
pm. Lens aberrations are corrected on-line during the experiment and by hardware such that resulting image distortions are below 80
pm. Consequently, the imaging can be aberration-free to this extent. The resolution enhancement results from increased electrical and mechanical stability of the instrument coupled with a low spherical aberration coefficient of 0.595+0.005
mm.