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http://hdl.handle.net/10773/24784
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DC Field | Value | Language |
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dc.contributor.author | Heras-Juaristi, G. | pt_PT |
dc.contributor.author | Amador, U. | pt_PT |
dc.contributor.author | Fuentes, R. O. | pt_PT |
dc.contributor.author | Chinelatto, A. L. | pt_PT |
dc.contributor.author | De Paz, J.Romero | pt_PT |
dc.contributor.author | Ritter, C. | pt_PT |
dc.contributor.author | Fagg, D. P. | pt_PT |
dc.contributor.author | Pérez-Coll, D. | pt_PT |
dc.contributor.author | Mather, Glenn C. | pt_PT |
dc.date.accessioned | 2018-11-30T15:16:33Z | - |
dc.date.available | 2018-11-30T15:16:33Z | - |
dc.date.issued | 2018 | - |
dc.identifier.issn | 2050-7488 | pt_PT |
dc.identifier.uri | http://hdl.handle.net/10773/24784 | - |
dc.description.abstract | A complete solid solution forms between the perovskite proton conductor BaZr0.7Ce0.2Y0.1O3-δ (BZCY72) and BaPr0.9Y0.1O3-δ (BPY) on synthesis by the Pechini method and high-temperature annealing. Phase fields of selected members of the Ba(Zr0.7Ce0.2)1-(x/0.9)PrxY0.1O3-δ series were studied as a function of composition and temperature by high-resolution neutron powder diffraction revealing symmetry changes in the sequence Pnma → Imma → → Pm3m. Higher symmetry is favoured for low Pr contents and high temperatures, as consideration of tolerance factor suggests. A volume contraction, ascribed to dehydration, is observed by synchrotron X-ray diffraction on heating in air for lower x. Magnetic measurements and structural data support the presence of Pr in the IV valence state on the perovskite B site. Thermogravimetric analysis in CO2 to ∼1253 K indicates better chemical stability for x ≤ 0.445, whereas decomposition occurred for higher x. Electrical conductivity increases by over two orders of magnitude in dry air at lower temperature from x = 0.225 to 0.675; total conductivity reaches a value of 0.4 S cm-1 at 1173 K for x = 0.675. The series exhibits electron-hole transport with a positive pO2 dependence which increases with temperature, consistent with participation of oxygen vacancies in charge compensation of the Y3+ acceptor dopant. The activation energy for thermally activated hole hopping in air in the range 523-773 K decreases from ∼1 eV for BZCY72 to ∼0.4 eV for x = 0.675. Conductivity is generally lower in humidified N2 and air (pH2O ≈ 0.023 atm) than the corresponding dry atmospheres, consistent with consumption of holes by less mobile protonic species; however for x ≤ 0.225 the lower concentration of electron holes concomitant with higher oxygen-vacancy content in N2 results in slightly higher conductivity in wet conditions due to hydration of vacancies. | pt_PT |
dc.language.iso | eng | pt_PT |
dc.publisher | Royal Society of Chemistry | pt_PT |
dc.relation | FCT-PTDC/CTM-ENE/6319/2014 | pt_PT |
dc.rights | restrictedAccess | pt_PT |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | pt_PT |
dc.title | Thermal evolution of structures and conductivity of Pr-substituted BaZr0.7Ce0.2Y0.1O3-:δ: Potential cathode components for protonic ceramic fuel cells | pt_PT |
dc.type | article | pt_PT |
dc.description.version | published | pt_PT |
dc.peerreviewed | yes | pt_PT |
ua.distribution | international | pt |
degois.publication.firstPage | 5324 | pt_PT |
degois.publication.issue | 13 | pt_PT |
degois.publication.lastPage | 5334 | pt_PT |
degois.publication.title | Journal of Materials Chemistry A | pt_PT |
degois.publication.volume | 6 | pt_PT |
dc.relation.publisherversion | https://pubs.rsc.org/en/content/articlelanding/2018/ta/c7ta09570h | pt_PT |
dc.identifier.doi | 10.1039/c7ta09570h | pt_PT |
dc.identifier.essn | 2050-7496 | pt_PT |
Appears in Collections: | TEMA - Artigos DEM - Artigos |
Files in This Item:
File | Description | Size | Format | |
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Thermal evolution of structures and conductivity of Pr-substituted BaZr0.7Ce0.2Y0.1O3δ Potential cathode components for protonic ceramic fuel cells.pdf | 1.19 MB | Adobe PDF |
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