13
Views
9
CrossRef citations to date
0
Altmetric
Articles

Interpretation of ESCA Thickness Measured on Non-Uniform Oxide Layers

Pages 135-138 | Published online: 19 Jul 2013
 

Abstract

The ESCA method of determining oxide layer thickness depends upon a comparison of the photoelectron intensity received from the overlayer of oxide with that from the unoxidised metal substrate underneath. As photoelectron intensity varies .nonlinearly with the depth of material, however, the method requires that the oxide be uniform in thickness. The errors caused by a non-uniform oxide layer are investigated theoretically for a flat plate. It is shown that the method always underestimates the mean thickness of irregular oxide layers. The error incurred is strongly dependent on the mean oxide thickness, becoming substantial when the layer is comparable in thickness to the inelastic mean free path of the electrons or thicker. Error calculations are given for several irregular oxide layers using a simple geometric model which assumes that the oxide consists of relatively thick islands interspersed on a thin oxide skin on the metal substrate. Results of measurements on gas atomised aluminium powder are interpreted and are shown to be consistent with the proposed model. PM/0542

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.