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Dostęp zamkniętyA structural study of Ruddlesden–Popper phases Sr3−xYx(Fe1.25Ni0.75)O7−δ with x ≤ 0.75 by neutron powder diffraction and EXAFS/XANES spectroscopy
| cris.lastimport.scopus | 2024-02-12T19:30:25Z |
| dc.abstract.en | The structures of Ruddlesden – Popper n ¼ 2 member phases Sr 3 ? x Y x Fe 1.25 Ni 0.75 O 7 ? d with 0 # x # 0.75 have been investigated using neutron powder di ff raction and K-edge Fe and Ni EXAFS/XANES spectroscopy in order to gain information about the evolution of the oxygen vacancy distribution and Fe/Ni oxidation state with x . Both samples prepared at 1300 ? C under a fl ow of N 2 (g), with d ¼ 1.41 – 1.00, and samples subsequently annealed in air at 900 ? C, with d ¼ 0.44 – 0.59, were characterized. The as-prepared x ¼ 0.75 phase has d ¼ 1, the O1 atom site is vacant, and the Fe 3+ /Ni 2+ ions have a square pyramidal coordination. With decreasing x the O3 occupancy decreases nearly linearly to 81% for x ¼ 0, while the O1 occupancy increases from 0 for x ¼ 0.4 to 33% for x ¼ 0. The air-annealed x ¼ 0.75 sample has a d value of 0.59 and the Fe 3+ /Fe 4+ /Ni 2+ /Ni 3+ ions have both square pyramidal and octahedral coordination. With decreasing x , the d value decreases to 0.45 for x ¼ 0, implying an increase in the oxidation states of Fe/Ni ions. EXAFS/XANES data show that for the as-prepared samples the coordination changes are predominantly for Ni 2+ ions and that the air-annealed samples contain both Fe 3+ /Fe 4+ |
| dc.affiliation | Uniwersytet Warszawski |
| dc.contributor.author | Bendicho, Jordi |
| dc.contributor.author | Carlsson, Stefan |
| dc.contributor.author | Svensson, Gunnar |
| dc.contributor.author | Janson, Kjell |
| dc.contributor.author | Wardecki, Dariusz |
| dc.contributor.author | Grins, Jekabs |
| dc.date.accessioned | 2024-01-24T18:13:17Z |
| dc.date.available | 2024-01-24T18:13:17Z |
| dc.date.issued | 2017 |
| dc.description.finance | Nie dotyczy |
| dc.identifier.doi | 10.1039/C7TA07113B |
| dc.identifier.issn | 2050-7488 |
| dc.identifier.uri | https://repozytorium.uw.edu.pl//handle/item/101881 |
| dc.language | eng |
| dc.pbn.affiliation | physical sciences |
| dc.relation.ispartof | Journal of Materials Chemistry A |
| dc.rights | ClosedAccess |
| dc.sciencecloud | nosend |
| dc.title | A structural study of Ruddlesden–Popper phases Sr3−xYx(Fe1.25Ni0.75)O7−δ with x ≤ 0.75 by neutron powder diffraction and EXAFS/XANES spectroscopy |
| dc.type | JournalArticle |
| dspace.entity.type | Publication |