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129606 https://hdl.handle.net/2286/R.I.25622 <p>Kormondy, Kristy J., Posadas, Agham B., Slepko, Alexander, Dhamdhere, Ajit, Smith, David J., Mitchell, Khadijih N., Willett-Gies, Travis I., Zollner, Stefan, Marshall, Luke G., Zhou, Jianshi, &amp; Demkov, Alexander A. (2014). Epitaxy of polar semiconductor Co3O4 (110): Growth, structure, and characterization. JOURNAL OF APPLIED PHYSICS, 115(24), 243708. http://dx.doi.org/10.1063/1.4885048</p> 10.1063/1.4885048 0021-8979 1089-7550 http://rightsstatements.org/vocab/InC/1.0/ 2014-06-28 9 pages eng Kormondy, Kristy J. Posadas, Agham B. Slepko, Alexander Dhamdhere, Ajit Smith, David Mitchell, Khadijih N. Willett-Gies, Travis I. Zollner, Stefan Marshall, Luke G. Zhou, Jianshi Demkov, Alexander A. College of Liberal Arts and Sciences Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. along with the following message: The following article appeared in 115, 24 (2014) and may be found at http://dx.doi.org/10.1063/1.4885048 <p>The (110) plane of Co₃O₄ spinel exhibits significantly higher rates of carbon monoxide conversion due to the presence of active Co³⁺ species at the surface. However, experimental studies of Co₃O₄ (110) surfaces and interfaces have been limited by the difficulties in growing high-quality films. We report thin (10–250 Å) Co₃O₄ films grown by molecular beam epitaxy in the polar (110) direction on MgAl₂O₄ substrates. Reflection high-energy electron diffraction, atomic force microscopy, x-ray diffraction, and transmission electron microscopy measurements attest to the high quality of the as-grown films. Furthermore, we investigate the electronic structure of this material by core level and valence band x-ray photoelectron spectroscopy, and first-principles density functional theory calculations. Ellipsometry reveals a direct band gap of 0.75 eV and other interband transitions at higher energies. A valence band offset of 3.2 eV is measured for the Co₃O₄/MgAl₂O₄ heterostructure. Magnetic measurements show the signature of antiferromagnetic ordering at 49 K. FTIR ellipsometry finds three infrared-active phonons between 300 and 700 cm^-1.</p> Text Epitaxy of Polar Semiconductor Co3O4 (110): Growth, Structure, and Characterization