TY - JOUR
T1 - Large-cluster-model calculation of O 1s XAS for Y2-xCa xBaNiO5
AU - Okada, Kozo
N1 - Funding Information:
This work was partially supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology.
PY - 2005/6
Y1 - 2005/6
N2 - The electronic structure of a quasi-one-dimensional nickelate, Y 2-xCaxBaNiO5, is discussed on the basis of numerically-exact diagonalization calculations of O 1s XAS using a four-site one-dimensional cluster model. In the undoped nickelate (x=0), the band dispersion along the chain direction is suppressed owing the intra-atomic Coulomb and exchange interactions between 3d holes. As a result, the width of the O 1s XAS peak that corresponds to the transition to the upper Hubbard band (UHB) is very narrow. Upon hole-doping, two new peaks appear about 2 eV below the UHB in accordance with the experiment. The dependence on the incident-photon polarization is also consistent with the experiment.
AB - The electronic structure of a quasi-one-dimensional nickelate, Y 2-xCaxBaNiO5, is discussed on the basis of numerically-exact diagonalization calculations of O 1s XAS using a four-site one-dimensional cluster model. In the undoped nickelate (x=0), the band dispersion along the chain direction is suppressed owing the intra-atomic Coulomb and exchange interactions between 3d holes. As a result, the width of the O 1s XAS peak that corresponds to the transition to the upper Hubbard band (UHB) is very narrow. Upon hole-doping, two new peaks appear about 2 eV below the UHB in accordance with the experiment. The dependence on the incident-photon polarization is also consistent with the experiment.
KW - Cluster model
KW - Electron correlation
KW - Exact diagonalization
KW - Exchange interaction
KW - O 1s XAS
KW - YCaBaNiO
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U2 - 10.1016/j.elspec.2005.01.005
DO - 10.1016/j.elspec.2005.01.005
M3 - Article
AN - SCOPUS:17444401367
SN - 0368-2048
VL - 144-147
SP - 1209
EP - 1213
JO - Journal of Electron Spectroscopy and Related Phenomena
JF - Journal of Electron Spectroscopy and Related Phenomena
ER -