On the importance of fifth-order spherical aberration for a fully corrected electron microscope

• Published in: Ultramicroscopy Vol. 106; no. 4; pp. 301 - 306
• Main Authors: Chang, L.Y., Kirkland, A.I., Titchmarsh, J.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2006
• Subjects: [formula omitted] and [formula omitted]-corrected microscope; Phase contrast theory; 07.78.+s; 07.60. - j; 07.05.Fb; C s and C c -corrected microscope; Phase contrast theory
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/j.ultramic.2005.09.004

Next generation aberration correctors will not only eliminate the third-order spherical aberration, but also improve the information limit by correction of chromatic aberration. As a result of these improvements, higher order aberrations, which have largely been neglected in image analysis, will become important. In this paper, we concern ourselves with situations where sub-Å resolution can be achieved, and where the third-order spherical aberration is corrected and the fifth-order spherical aberration is measurable. We derive formulae to explore the maximum value of the fifth-order spherical aberration for directly interpretable imaging and discuss the optimum imaging conditions and their applicable range.