https://doi.org/10.1140/epjb/e20020113
The electronic structure of the doped one-dimensional transition metal oxide Y2-xCaxBaNiO5 studied using X-ray absorption
1
Institute for Solid State Research, IFW Dresden, 01171 Dresden, Germany
2
Department of Inorganic Chemistry, University of Utrecht
Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands
3
Correlated Electron Research Center, AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan
4
Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin,
Germany
Corresponding author: a m.knupfer@ifw-dresden.de
Received:
7
January
2002
Published online: 15 April 2002
A strong anisotropic distribution of the holes in Ni 3d and O 2p orbitals is observed in the polarization dependent O 1s and Ni X-ray absorption spectroscopy of the linear-chain nickelate Y2-xCaxBaNiO5 (x = 0, 0.05, 0.1, 0.2), which demonstrates the one-dimensional
nature of the electronic state in these compounds. The holes introduced by Ca-doping occupy
both O 2p and Ni 3d orbitals along the NiO5 chains. By comparing the experimental Ni
absorption spectra of Y2-xCaxBaNiO5 to those from charge transfer multiplet calculations we can derive the orbital character of the additional holes to be of ~60% O2p and ~40% Ni 3d.
PACS: 78.70.Dm – X-ray absorption spectra / 71.28.+d – Narrow-band systems; intermediate-valence solids / 79.60.-i – Photoemission and photoelectron spectra
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002