TY - JOUR
T1 - Soft X-ray absorption spectroscopy study of (Ba0.5Sr0.5) (Co0.8Fe0.2)1-xNbxO3-δ with different content of Nb (5%-20%)
AU - Egorova, Y.V.
AU - Scherb, T.
AU - Schumacher, G.
AU - Bouwmeester, H.J.M.
AU - Filatova, E.O.
N1 - Funding Information:
The authors acknowledge financial support from the German-Russian Interdisciplinary Science Center (G-RISC, DAAD, projects P-2013a-8 , P-2014a-11 ). We thank HZB for the allocation of synchrotron radiation beamtime. Support from Helmholtz-Association through the Helmholtz-Alliance MEM-BRAIN is also gratefully acknowledged.
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/8/22
Y1 - 2015/8/22
N2 - The mixed electronic ionic conducting materials (Ba0.5Sr0.5) (Co0.8Fe0.2)1-xNbxO3-δ with partial Nb substitution (x: 0.05, 0.10, 0.15, 0.20) for B cations (Co/Fe), synthesized using a solid state reaction method, have been studied by near edge X-ray absorption fine structure (NEXAFS). Co L2,3- absorption spectra of (Ba0.5Sr0.5) (Co0.8Fe0.2)1-xNbxO3-δ (BSCFN) powders were analyzed with the purpose to understand the influence of the Nb substitution on the atomic electronic structure of BSCFN. The joint analysis of the Co L2,3- absorption spectra reveals the presence of mixed oxidation states Co2+/Co3+ in all the studied BSCFN structures. It was established that the proportion of oxidation states Co2+/Co3+ and the corresponding coordinations of Co atoms depend on the content of Nb. In the 10% Nb substituted BSCF sample Co atoms mostly occur in the Co2+ oxidation state and are preferentially characterized by an octahedral coordination site. In all other structures Co atoms are rather characterized by Co2+/Co3+ oxidation states and occupy both octahedrally and tetrahedrally coordinated sites.
AB - The mixed electronic ionic conducting materials (Ba0.5Sr0.5) (Co0.8Fe0.2)1-xNbxO3-δ with partial Nb substitution (x: 0.05, 0.10, 0.15, 0.20) for B cations (Co/Fe), synthesized using a solid state reaction method, have been studied by near edge X-ray absorption fine structure (NEXAFS). Co L2,3- absorption spectra of (Ba0.5Sr0.5) (Co0.8Fe0.2)1-xNbxO3-δ (BSCFN) powders were analyzed with the purpose to understand the influence of the Nb substitution on the atomic electronic structure of BSCFN. The joint analysis of the Co L2,3- absorption spectra reveals the presence of mixed oxidation states Co2+/Co3+ in all the studied BSCFN structures. It was established that the proportion of oxidation states Co2+/Co3+ and the corresponding coordinations of Co atoms depend on the content of Nb. In the 10% Nb substituted BSCF sample Co atoms mostly occur in the Co2+ oxidation state and are preferentially characterized by an octahedral coordination site. In all other structures Co atoms are rather characterized by Co2+/Co3+ oxidation states and occupy both octahedrally and tetrahedrally coordinated sites.
KW - Local bonding environment
KW - Microstructure
KW - Near edge X-ray absorption fine structure
KW - Solid oxide fuel cell
KW - 2023 OA procedure
UR - http://www.scopus.com/inward/record.url?scp=84939632711&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2015.08.073
DO - 10.1016/j.jallcom.2015.08.073
M3 - Article
SN - 0925-8388
VL - 650
SP - 848
EP - 852
JO - Journal of alloys and compounds
JF - Journal of alloys and compounds
ER -