Revisiting the valence-band and core-level photoemission spectra of NiO.
We have reexamined the valence-band (VB) and core-level electronic structure of NiO by means of hard and soft x-ray photoemission spectroscopies. The spectral weight of the lowest energy state was found to be enhanced in the bulk sensitive Ni 2p core-level spectrum. A configuration-interaction model including a bound state screening has shown agreement with the core-level spectrum and off- and on-resonance VB spectra. These results identify the lowest energy states in the core-level and VB spectra as the Zhang-Rice (ZR) doublet bound states, consistent with the spin-fermion model and recent ab initio calculations within dynamical mean-field theory. The results indicate that the ZR character first ionization (the lowest hole-addition) states are responsible for transport properties in NiO and doped NiO.
Soft X-ray Spectroscopy Lab, RIKEN SPring-8 Center, Sayo, Sayo, Hyogo 679-5148, Japan.
M
M
Taguchi
M
M
Matsunami
Y
Y
Ishida
R
R
Eguchi
A
A
Chainani
Y
Y
Takata
M
M
Yabashi
K
K
Tamasaku
Y
Y
Nishino
T
T
Ishikawa
Y
Y
Senba
H
H
Ohashi
S
S
Shin