Effect of Cr substitution on the electronic structure of CuAl1-xCrxO2.
PHYS REV B
The geometries and electronic structures of CuAl1-xCrxO2 have been investigated using density-functional theory with on-site corrections for strongly correlated systems (GGA+U) for x=0,1/2,1. Al is found to be well described within the ionic model, with a valence charge corresponding to a +3 oxidation state. Substituting Cr for Al is predicted to increase the density of states at the top of the valence band, in agreement with experimental x-ray photoemission spectroscopy data. Analysis of atom-projected densities of states and valence charges suggests that this is due to increased covalency between Cr and O; the valence charge for O in the Cu-O-(Al,Cr) subunits changes from -1.74 to similar to-1.25 when Cr replaces Al. This produces an indirect oxygen-mediated change to the Cu d states.
|Title:||Effect of Cr substitution on the electronic structure of CuAl1-xCrxO2|
|Keywords:||aluminium compounds, chromium, copper compounds, density functional theory, doping, electronic density of states, oxidation, strongly correlated electron systems, valence bands, X-ray photoelectron spectra, CRYSTAL-STRUCTURE, THIN-FILMS, TRANSPARENT, CUALO2, OXIDE, SEMICONDUCTOR, 1ST-PRINCIPLES, CONDUCTIVITY, GRADIENT, CUGAO2|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry
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