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

作者：Mock Alyssa; Korlacki Rafal; Briley Chad; Sekora Derek; Hofmann Tino; Wilson Peter; Sinitskii Alexander; Schubert Eva; Schubert Mathias

来源：Applied Physics Letters, 2016, 108(5): 051905.

DOI：10.1063/1.4941399

Highly ordered and spatially coherent cobalt slanted columnar thin films (SCTFs) were deposited by glancing angle deposition onto silicon substrates, and subsequently oxidized by annealing at 475 degrees 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 Co-Al2O3 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 degrees C.

• 出版日期2016-2-1