Atomic Dynamics of Multi‐Interfacial Migration and Transformations
[1]
- Department of Mechanical Engineering &, Materials Science and Engineering Program State University of New York Binghamton NY 13902 USA
- Department of Mechanical Engineering and Materials Science University of Pittsburgh Pittsburgh PA 15216 USA
- Materials Science and Engineering Division National Institute of Standards and Technology Gaithersburg MD 20899 USA
- Department of Chemical and Petroleum Engineering University of Pittsburgh Pittsburgh PA 15261 USA
Abstract Redox‐induced interconversions of metal oxidation states typically result in multiple phase boundaries that separate chemically and structurally distinct oxides and suboxides. Directly probing such multi‐interfacial reactions is challenging because of the difficulty in simultaneously resolving the multiple reaction fronts at the atomic scale. Using the example of CuO reduction in H 2 gas, a reaction pathway of CuO → monoclinic m‐Cu 4 O 3 → Cu 2 O is demonstrated and identifies interfacial reaction fronts at the atomic scale, where the Cu 2 O/m‐Cu 4 O 3 interface shows a diffuse‐type interfacial transformation; while the lateral flow of interfacial ledges appears to control the m‐Cu 4 O 3 /CuO transformation. Together with atomistic modeling, it is shown that such a multi‐interface transformation results from the surface‐reaction‐induced formation of oxygen vacancies that diffuse into deeper atomic layers, thereby resulting in the formation of the lower oxides of Cu 2 O and m‐Cu 4 O 3 , and activate the interfacial transformations. These results demonstrate the lively dynamics at the reaction fronts of the multiple interfaces and have substantial implications for controlling the microstructure and interphase boundaries by coupling the interplay between the surface reaction dynamics and the resulting mass transport and phase evolution in the subsurface and bulk.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- NONE; SC0001135; SC0012704
- OSTI ID:
- 2324695
- Journal Information:
- Small, Journal Name: Small Journal Issue: 11 Vol. 20; ISSN 1613-6810
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
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