The mystery of missing species in atom probe tomography of composite materials

Journal Article · Mon Aug 10 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4928625· OSTI ID:22489087

Karahka, M.; Xia, Y.; Kreuzer, H. J. ^[1]

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1. Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 3J5 (Canada)

There is a serious problem in atom probe tomography of composite materials such as oxides that even from stoichiometric samples one observes non-stoichiometric ion yields. We present a quantitative model that explains the non-stoichiometry allowing a fit to experimental data of ion yields as a function of applied field to extract activation barriers and prefactors. The numbers are confirmed by density functional theory. We also show that for oxides the missing oxygen is thermally desorbed as neutral O{sub 2}, either directly or associatively. Finally, we suggest methods to improve the experimental setup.

• OSTI ID: 22489087
• Journal Information: Applied Physics Letters, Vol. 107, Issue 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMS
COMPOSITE MATERIALS
DENSITY FUNCTIONAL METHOD
DIFFUSION BARRIERS
OXIDES
OXYGEN
PROBES
STOICHIOMETRY
TOMOGRAPHY