Electronic structure origin of conductivity and oxygen reduction activity changes in low-level Cr-substituted (La,Sr)MnO.sub.3./sub.

0456505 - FZÚ 2016 RIV US eng J - Journal Article
Tsekouras, G. - Boudoire, F. - Pal, B. - Vondráček, Martin - Prince, K. C. - Sarma, D.D. - Braun, A.
Electronic structure origin of conductivity and oxygen reduction activity changes in low-level Cr-substituted (La,Sr)MnO₃.
Journal of Chemical Physics. Roč. 143, č. 11 (2015), s. 114705. ISSN 0021-9606. E-ISSN 1089-7690
R&D Projects: GA MŠMT LO1409; GA MŠMT(CZ) LM2011029
Institutional support: RVO:68378271
Keywords : X-ray-absorption * thin-films * spectroscopy * photoemission * La_1-xSr_xMnO₃ * oxide * manganite * cathodes
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.894, year: 2015

The electronic structure of the (La0,8Sr0,2)0,98Mn1-xCr03 model series (x = 0, 0.05, or 0.1) was measured using soft X-ray synchrotron radiation at room and elevated temperature. O K-edge nearedge X-ray absorption fine structure (NEXAFS) spectra showed that low-level chromium substitution of (La,Sr)MnO3 resulted in lowered hybridisation between O 2p orbitals and M 3d and M 4sp valance orbitals. Mn L3-edge resonant photoemission spectroscopy measurements indicated lowered Mn 3d–O 2p hybridisation with chromium substitution. Deconvolution of O K-edge NEXAFS spectra took into account the effects of exchange and crystal field splitting and included a novel approach whereby the pre-peak region was described using the nominally filled t2g state. 10% chromium substitution resulted in a 0.17 eV lowering in the energy of the t2g state.
Permanent Link: http://hdl.handle.net/11104/0257018