dc.identifier.uri |
http://dx.doi.org/10.15488/13994 |
|
dc.identifier.uri |
https://www.repo.uni-hannover.de/handle/123456789/14108 |
|
dc.contributor.author |
Kanas, Nikola
|
|
dc.contributor.author |
Williamson, Benjamin A. D.
|
|
dc.contributor.author |
Steinbach, Frank
|
|
dc.contributor.author |
Hinterding, Richard
|
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dc.contributor.author |
Einarsrud, Mari-Ann
|
|
dc.contributor.author |
Selbach, Sverre M.
|
|
dc.contributor.author |
Feldhoff, Armin
|
|
dc.contributor.author |
Wiik, Kjell
|
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dc.date.accessioned |
2023-06-29T07:13:06Z |
|
dc.date.available |
2023-06-29T07:13:06Z |
|
dc.date.issued |
2022 |
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dc.identifier.citation |
Kanas, N.; Williamson, B.A.D.; Steinbach, F.; Hinterding, R.; Einarsrud, M.-A. et al.: Tuning the Thermoelectric Performance of CaMnO3-Based Ceramics by Controlled Exsolution and Microstructuring. In: ACS Applied Energy Materials 5 (2022), Nr. 10, S. 12396-12407. DOI: https://doi.org/10.1021/acsaem.2c02012 |
|
dc.description.abstract |
The thermoelectric properties of CaMnO3-δ/CaMn2O4 composites were tuned via microstructuring and compositional adjustment. Single-phase rock-salt-structured CaO-MnO materials with Ca:Mn ratios larger than unity were produced in reducing atmosphere and subsequently densified by spark plasma sintering in vacuum. Annealing in air at 1340 °C between 1 and 24 h activated redox-driven exsolution and resulted in a variation in microstructure and CaMnO3-δ materials with 10 and 15 vol % CaMn2O4, respectively. The nature of the CaMnO3-δ/CaMn2O4 grain boundary was analyzed by transmission electron microscopy on short- and long-term annealed samples, and a sharp interface with no secondary phase formation was indicated in both cases. This was further complemented by density functional theory (DFT) calculations, which confirmed that the CaMnO3-δ indeed is a line compound. DFT calculations predict segregation of oxygen vacancies from the bulk of CaMnO3-δ to the interface between CaMnO3-δ and CaMn2O4, resulting in an enhanced electronic conductivity of the CaMnO3-δ phase. Samples with 15 vol % CaMn2O4 annealed for 24 h reached the highest electrical conductivity of 73 S·cm-1 at 900 °C. The lowest thermal conductivity was obtained for composites with 10 vol % CaMn2O4 annealed for 8 h, reaching 0.56 W·m-1K-1 at 700 °C. However, the highest thermoelectric figure-of-merit, zT, was obtained for samples with 15 vol % CaMn2O4 reaching 0.11 at temperatures between 800 and 900 °C, due to the enhanced power factor above 700 °C. This work represents an approach to boost the thermoelectric performance of CaMnO3-δ based composites. |
eng |
dc.language.iso |
eng |
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dc.publisher |
Washington, DC : ACS Publications |
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dc.relation.ispartofseries |
ACS Applied Energy Materials 5 (2022), Nr. 10 |
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dc.rights |
CC BY 4.0 Unported |
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dc.rights.uri |
https://creativecommons.org/licenses/by/4.0 |
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dc.subject |
composite CaMnO 3-δ |
eng |
dc.subject |
electrical conductivity |
eng |
dc.subject |
heterostructuring |
eng |
dc.subject |
oxide thermoelectrics |
eng |
dc.subject |
thermal conductivity |
eng |
dc.subject.ddc |
540 | Chemie
|
|
dc.title |
Tuning the Thermoelectric Performance of CaMnO3-Based Ceramics by Controlled Exsolution and Microstructuring |
eng |
dc.type |
Article |
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dc.type |
Text |
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dc.relation.essn |
2574-0962 |
|
dc.relation.issn |
2574-0962 |
|
dc.relation.doi |
https://doi.org/10.1021/acsaem.2c02012 |
|
dc.bibliographicCitation.issue |
10 |
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dc.bibliographicCitation.volume |
5 |
|
dc.bibliographicCitation.firstPage |
12396 |
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dc.bibliographicCitation.lastPage |
12407 |
|
dc.description.version |
publishedVersion |
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tib.accessRights |
frei zug�nglich |
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