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X-ray spectroscopic study of the electronic structure of CuCrO 2

2009; American Physical Society; Volume: 79; Issue: 7 Linguagem: Inglês

10.1103/physrevb.79.075102

1550-235X

Thomas Arnold, David J. Payne, A. Bourlange, Jingping Hu, R.G. Egdell, Louis F. J. Piper, Leyla Çolakerol Arslan, Anna De Masi, Per‐Anders Glans, T. Learmonth, Kevin E. Smith, Jinghua Guo, David O. Scanlon, Aron Walsh, Benjamin J. Morgan, Graeme W. Watson,

Electronic and Structural Properties of Oxides

The electronic structure of the $p$-type transparent conducting oxide ${\text{CuCrO}}_{2}$ has been studied by x-ray photoemission, x-ray absorption, and x-ray emission spectroscopies. The upper part of the valence band derives mainly from $\text{Cu}\text{ }3d$ and $\text{Cr}\text{ }3d$ states while the lower valence-band states are of dominant $\text{O}\text{ }2p$ atomic character, but with pronounced mutual hybridization among $\text{Cu}\text{ }3d$, $\text{Cr}\text{ }3d$, and $\text{O}\text{ }2p$ states. Site specific electronic excitations have been studied by resonant inelastic x-ray scattering at the $\text{Cu}\text{ }L$ and $\text{Cr}\text{ }L$ edges. Inelastic loss at the $\text{Cu}\text{ }L$ edge is dominated by on-site interband excitations similar to those found in ${\text{Cu}}_{2}\text{O}$, while at the $\text{Cr}\text{ }L$ edge localized excitations arising from ligand field splitting of the $\text{Cr}\text{ }3d$ levels are observed. Mg doping on the Cr sites in ${\text{CuCrO}}_{2}$ is shown to lead to a pronounced shift in the Fermi level toward the edge of the valence band. The experimental data are compared to electronic structure calculations on ${\text{CuCrO}}_{2}$ carried out using density-functional methods corrected for onsite Coulomb repulsion.