Towards sub-0.5 Å electron beams

• Published in: Ultramicroscopy 2003-09, Vol.96 (3), p.229-237
• Main Authors: Krivanek, O.L., Nellist, P.D., Dellby, N., Murfitt, M.F., Szilagyi, Z.
• Format: Article
• Language: English
• Subjects: Aberration correction; Condensed matter: structure, mechanical and thermal properties; Electron microscopy; Electron, ion, and scanning probe microscopy; Electron, positron and ion microscopes, electron diffractometers and related techniques; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Quadrupole–octupole corrector; Scanning transmission electron microscopy; Structure of solids and liquids; crystallography; Transmission, reflection and scanning electron microscopy(including ebic)
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/S0304-3991(03)00090-1

In the 4 years since the previous meeting in the SALSA series, aberration correction has progressed from a promising concept to a powerful research tool. We summarize the factors that have enabled 100–120 kV scanning transmission electron microscopes to achieve sub-Å resolution, and to increase the current available in an atom-sized probe by a factor of 10 and more. Once C s is corrected, fifth-order spherical aberration ( C 5) and chromatic aberration ( C c) pose new limits on resolution. We describe a quadrupole/octupole corrector of a new design, which will correct all fifth-order aberrations while introducing less than 0.2 mm of additional C c. Coupled to an optimized STEM column, the new corrector promises to lead to routine sub-Å electron probes at 100 kV, and to sub-0.5 Å probes at higher operating voltages.