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The electronic structure of the doped one-dimensional transition metal oxide Y1-xCaxBaNiO5 studied using x-ray absorption

Z. Hu·M. Knupfer·M. Kielwein·U. K. Roessler·M. S. Golden·J. Fink·F. M. F. de Groot·T. Ito·G. Kaindl
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Abstract

A strong anisotropic distribution of the holes in Ni 3d and O 2p orbitals is observed in the polarization dependent O1s and Ni2p3/2 x-ray absorption spectroscopy of the linear-chain nickelate Y1-xCaxBaNiO5 (x = 0, 0.05, 0.1, 0.2), which demonstrates the one-dimensional nature of the electronic state in these compounds. Furthermore, the additional holes introduced by Ca-doping occupy both O 2p and Ni 3d orbitals along the NiO5 chains. By comparing the experimental Ni 2p3/2 absorption spectra of Y1-xCaxBaNiO5 to those from charge transfer multiplet calculations we can derive the orbital character of the additional holes to be of ca. 60% O2p and ca. 40% Ni 3d.

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Z. Hu, M. Knupfer, M. Kielwein, U. K. Roessler, M. S. Golden, J. Fink, F. M. F. de Groot, T. Ito, G. Kaindl. 2001-08-08. The electronic structure of the doped one-dimensional transition metal oxide Y1-xCaxBaNiO5 studied using x-ray absorption. https://doi.org/10.1140/epjb%2Fe20020113

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