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arXiv · 1512.01860

Anisotropy, band-to-band transitions, phonon modes, and oxidation properties of cobalt-oxide core-shell slanted columnar thin films

Alyssa Mock·Rafal Korlacki·Chad Briley·Derek Sekora·Tino Hofmann·Peter Wilson·Alexander Sinitskii·Eva Schubert·Mathias Schubert
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Abstract

Highly-ordered and spatially-coherent cobalt slanted columnar thin films were deposited by glancing angle deposition onto silicon substrates, and subsequently oxidized by annealing at 475 $^{\circ}$C. Scanning electron microscopy, Raman scattering, generalized ellipsometry, and density functional theory investigations reveal shape-invariant transformation of the slanted nanocolumns from metallic to transparent metal-oxide core-shell structures with properties characteristic of spinel cobalt oxide. We find passivation of Co-SCTFs yielding CoAl$_2$O$_3$ core-shell structures produced by conformal deposition of a few nanometers of alumina using atomic layer deposition fully prevents cobalt oxidation in ambient and from annealing up to 475 $^{\circ}$C.

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Alyssa Mock, Rafal Korlacki, Chad Briley, Derek Sekora, Tino Hofmann, Peter Wilson, Alexander Sinitskii, Eva Schubert, Mathias Schubert. 2015-12-06. Anisotropy, band-to-band transitions, phonon modes, and oxidation properties of cobalt-oxide core-shell slanted columnar thin films. https://doi.org/10.1063/1.4941399

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