Interpreting atom probe data from chromium oxide scales.

Authors :: La Fontaine A
Gault B
Breen A
Stephenson L
Ceguerra AV
Yang L
Nguyen TD
Zhang J
Young DJ
Cairney JM
Source :: Ultramicroscopy [Ultramicroscopy] 2015 Dec; Vol. 159 Pt 2, pp. 354-9. Date of Electronic Publication: 2015 Feb 14.
Publication Year :: 2015
Abstract: Picosecond-pulsed ultraviolet-laser (UV-355 nm) assisted atom probe tomography (APT) was used to analyze protective, thermally grown chromium oxides formed on stainless steel. The influence of analysis parameters on the thermal tail observed in the mass spectra and the chemical composition is investigated. A new parameter termed "laser sensitivity factor" is introduced in order to quantify the effect of laser energy on the extent of the thermal tail. This parameter is used to compare the effect of increasing laser energy on thermal tails in chromia and chromite samples. Also explored is the effect of increasing laser energy on the measured oxygen content and the effect of specimen base temperature and laser pulse frequency on the mass spectrum. Finally, we report a preliminary analysis of molecular ion dissociations in chromia.<br /> (Copyright © 2015 Elsevier B.V. All rights reserved.)