Title
Efficient creation of electron vortex beams for high resolution STEM imaging Efficient creation of electron vortex beams for high resolution STEM imaging
Author
Faculty/Department
Faculty of Sciences. Physics
Publication type
article
Publication
Amsterdam ,
Subject
Physics
Source (journal)
Ultramicroscopy. - Amsterdam
Volume/pages
(2016) , p. 1-8
ISSN
0304-3991
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the AharonovBohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angström, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument.
Full text (open access)
https://repository.uantwerpen.be/docman/irua/1b4ce5/134085.pdf
E-info
https://repository.uantwerpen.be/docman/iruaauth/571d34/134085.pdf
Handle