title: XANES study on Ruddlesden-Popper phase, La(n+1)Ni(n)O(3n+1) (n=1,2 and infinity).
abstract: Ruddlesden-Popper phase, La(n+1)Ni(n)O(3n+1 (n=1, 2, and infinity) compounds were prepared by citrate sol-gel method. We revealed the origin of the variation of the electrical conductivities in La(n+1)Ni(n)O(3n+1 (n=1, 2, and infinity) using resistivity measurements, Rietveld analysis, and X-ray absorption spectroscopy. According to the XANES spectra, it is found that the degree of 4p(pi) - 4psigma energy splitting between 8345 eV and 8350 eV is qualitatively proportional to the elongation of the out-of-plane Ni-O bond length. With the decrease of 4p(pi) - 4psigma splitting, the strong hybridization of the sigma-bonding between Ni-3d and O-2p orbitals creates narrow antibonding sigma* bands, which finally results in the lower electrical resistivity.
authors.affiliation: Department of Chemistry of New Materials, College of Natural Sciences, Silla University, Pusan, Korea. jcpark@silla.ac.kr
authors.forename: J C
authors.initials: JC
authors.lastname: Park
authors.forename: D K
authors.initials: DK
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Byeon
authors.forename: D
authors.initials: D
authors.lastname: Kim