| Autor: |
Blanchet MD; Department of Physics, Auburn University, Auburn, AL 36849, United States of America., Heath JJ, Kaspar TC, Matthews BE, Spurgeon SR, Bowden ME, Heald SM, Issacs-Smith T, Kuroda MA, Comes RB |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2021 Jan 13; Vol. 33 (12), pp. 124002. Date of Electronic Publication: 2021 Jan 13. |
| DOI: |
10.1088/1361-648X/abd573 |
| Abstrakt: |
Recent investigations on spinel CoMn 2 O 4 have shown its potential for applications in water splitting and fuel cell technologies as it exhibits strong catalytic behavior through oxygen reduction reactivity. To further understand this material, we report for the first time the synthesis of single-crystalline Co 1+x Mn 2-x O 4 thin films using molecular beam epitaxy. By varying sample composition, we establish links between cation stoichiometry and material properties using in-situ x-ray photoelectron spectroscopy, x-ray diffraction, scanning transmission electron microscopy, x-ray absorption spectroscopy, and spectroscopic ellipsometry. Our results indicate that excess Co ions occupy tetrahedral interstitial sites at lower excess Co stoichiometries, and become substitutional for octahedrally-coordinated Mn at higher Co levels. We compare these results with density functional theory models of stoichiometric CoMn 2 O 4 to understand how the Jahn-Teller distortion and hybridization in Mn-O bonds impact the ability to hole dope the material with excess Co. The findings provide important insights into CoMn 2 O 4 and related spinel oxides that are promising candidates for inexpensive oxygen reduction reaction catalysts. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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