Journal Article

FZJ-2015-02344

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Model-independent measurement of the charge density distribution along an Fe atom probe needle using off-axis electron holography without mean inner potential effects

Migunov, V. (Corresponding Author)FZJ* ; London, A. ; Farle, M. ; Dunin-Borkowski, R.FZJ*

2015
American Inst. of Physics Melville, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/16796  doi:10.1063/1.4916609

Abstract: The one-dimensional charge density distribution along an electrically biased Fe atom probe needle is measured using a model-independent approach based on off-axis electron holography in the transmission electron microscope. Both the mean inner potential and the magnetic contribution to the phase shift are subtracted by taking differences between electron-optical phase images recorded with different voltages applied to the needle. The measured one-dimensional charge density distribution along the needle is compared with a similar result obtained using model-based fitting of the phase shift surrounding the needle. On the assumption of cylindrical symmetry, it is then used to infer the three-dimensional electric field and electrostatic potential around the needle with ∼10 nm spatial resolution, without needing to consider either the influence of the perturbed reference wave or the extension of the projected potential outside the field of view of the electron hologram. The present study illustrates how a model-independent approach can be used to measure local variations in charge density in a material using electron holography in the presence of additional contributions to the phase, such as those arising from changes in mean inner potential and specimen thickness.

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Contributing Institute(s):

1. Mikrostrukturforschung (PGI-5)

Research Program(s):

1. 143 - Controlling Configuration-Based Phenomena (POF3-143) (POF3-143)

Appears in the scientific report 2015

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Database coverage:
; ; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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