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Aging Effects of As-deposited and Passivated Cobalt Slanted Columnar Thin Films

Published online by Cambridge University Press:  27 February 2012

Daniel Schmidt
Affiliation:
Department of Electrical Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, U.S.A.
Eva Schubert
Affiliation:
Department of Electrical Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, U.S.A.
Mathias Schubert
Affiliation:
Department of Electrical Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, U.S.A.
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Abstract

Aging effects of as-deposited and passivated slanted columnar thin films from cobalt determined by generalized ellipsometry within the visible spectral region are reported. Slanted columnar thin films have been grown by glancing angle electron beam deposition and sub-sequently coated with Al2O3 by an atomic layer deposition process. An anisotropic Bruggeman effective medium approximation developed for highly ordered three dimensional metal nanostructures is employed to analyze spectroscopic Mueller matrix ellipsometry data. Our model approach allows for determination of biaxial optical and structural properties as well as fractions of multiple film constituents. While the optical properties of the uncoated film change over time, the alumina passivation layer prevents oxidation in air and therefore aging effects; however, it affects the intrinsic bulk-like Co optical properties.

Type
Research Article
Copyright
Copyright © Materials Research Society 2012

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