Hostname: page-component-77c89778f8-7drxs Total loading time: 0 Render date: 2024-07-18T17:26:13.496Z Has data issue: false hasContentIssue false
  • English
  • Français

Progress in Aberration-Corrected STEM

Published online by Cambridge University Press:  02 July 2020

N. Dellby ,
O.L. Krivanek  and
A.R. Lupini
N. Dellby
Affiliation:
Nion Co., 1102 8th St., Kirkland, WA98033USA
O.L. Krivanek
Affiliation:
Nion Co., 1102 8th St., Kirkland, WA98033USA
A.R. Lupini
Affiliation:
Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge, CB3 0HEUK
Get access

Extract

Electron probe formation in a scanning transmission electron microscope (STEM) has two properties that maximize the benefits of spherical aberration correction: the smallest and brightest probes are formed when all the geometric aberrations are set to zero, and the size of the probe is not greatly affected by the presence of chromatic aberration. This contrasts with the case of conventional, fixed-beam TEM (CTEM), in which optimized phase-contrast imaging demands a non-zero spherical aberration coefficient (Cs), and chromatic aberration constitutes a major resolution limit. As a result, a consensus is presently emerging that the benefits of aberration correction will be felt most strongly in STEM.

Our efforts in Cs-corrected STEM have progressed from a proof-of-principle Cs corrector [1] to an optimized second-generation design [2]. The corrector in both cases is of the quadrupole-octupole type. The second-generation corrector uses separate quadrupoles and octupoles, and concentrates on maximizing the octupole strength.

Type
The Theory and Practice of Scanning Transmission Electron Microscopy
Information
Microscopy and Microanalysis , Volume 6 , Issue S2: Proceedings: Microscopy & Microanalysis 2000, Microscopy Society of America 58th Annual Meeting, Microbeam Analysis Society 34th Annual Meeting, Microscopical Society of Canada/Societe de Microscopie de Canada 27th Annual Meeting, Philadelphia, Pennsylvania August 13-17, 2000 , August 2000 , pp. 100 - 101
Copyright
Copyright © Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Krivanek, O.L. et al., IoP Conference Series (Ed. Rodenburg, J. M.) 153 (1997) 35.Google Scholar
2.Krivanek, O.L., Dellby, N. and Lupini, A.R., Ultramicroscopy 78 (1999) 1.CrossRefGoogle Scholar
3.Krivanek, O.L., Dellby, N. and Lupini, A.R., Proc. 57th MSA, Micr. and Microan. 5 (1999) 670.CrossRefGoogle Scholar
4.Beck, V. and Crewe, A.V., Proc. 32nd EMSA (1974) 426.CrossRefGoogle Scholar
5.Beck, V. and Crewe, A.V., Proc. 34th EMSAGoogle Scholar
6.Beck, V., Proc. 35th EMSA (1977) 90.CrossRefGoogle Scholar