Character of the insulating state in NiO: A mixture of charge-transfer and Mott-Hubbard character
| Autor: | Thomas A. Callcott, G. T. Woods, D. L. Ederer, T. M. Schuler, Joseph C. Woicik, S. Itza-Ortiz |
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| Rok vydání: | 2005 |
| Předmět: |
Valence (chemistry)
Materials science Absorption spectroscopy Condensed matter physics X-ray photoelectron spectroscopy Hubbard model Band gap Non-blocking I/O Condensed Matter::Strongly Correlated Electrons Fermi energy Electronic structure Condensed Matter Physics Electronic Optical and Magnetic Materials |
| Zdroj: | Physical Review B. 71 |
| ISSN: | 1550-235X 1098-0121 |
| Popis: | Using site-specific soft x-ray emission and absorption spectroscopy in conjunction with site-specific x-ray photoelectron spectroscopy, we present measurements of the valence and conduction band states of NiO. Significant hybridization between the Ni and the O electronic states near the Fermi energy is observed throughout both the valence and conduction bands, in accordance with density-functional theory calculations also presented. The relationship between our emission and absorption measurements also shows direct similarities to other techniques used to measure the non-dipole-allowed $d\text{\penalty1000-\hskip0pt}d$ transitions within NiO, addressing questions concerning the character of the insulating band gap of this system. NiO has previously been described as a large-gap, charge-transfer insulator, while our data show the valence and conduction states at the Fermi energy to be primarily of Ni $d$--character hybridized with a small amount of O $p$--character states, suggesting a mixture of charge-transfer and Mott-Hubbard character as described by the Zaanen-Sawatzky-Allen model. |
| Databáze: | OpenAIRE |
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