Nature of Defect States in Nitrogen-Doped MgO
| Autor: | Cristiana Di Valentin, Gianfranco Pacchioni, Matteo Pesci, Federico Gallino |
|---|---|
| Přispěvatelé: | Pesci, M, Gallino, F, DI VALENTIN, C, Pacchioni, G |
| Rok vydání: | 2009 |
| Předmět: |
chemistry.chemical_classification
MgO defects ab initio theory Magnesium chemistry.chemical_element Electron donor Electronic structure Electron acceptor Molecular physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Condensed Matter::Materials Science chemistry.chemical_compound General Energy chemistry Impurity Condensed Matter::Superconductivity Physics::Atomic and Molecular Clusters Cluster (physics) Density functional theory Physical and Theoretical Chemistry Atomic physics Spin (physics) |
| Zdroj: | The Journal of Physical Chemistry C. 114:1350-1356 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp9097556 |
| Popis: | The nature of nitrogen-doped MgO, N-MgO, is investigated by density functional theory (DFT) calculations using both periodic supercells and emebedded Cluster models. The electronic structure and the spin properties, in particular, the hyperfine coupling constants, of substitutional for O and interstitial N species are determined by using a hybrid exchange-correlation functional in order to account for the self-interaction problem in DFT. Both substitutional and interstitial N introduce magnetic impurities in bulk MgO and generate new energy levels at about 0.5-1.7 eV above the top of the MgO valence band. We have also considered the Simultaneous presence of neutral magnesium vacancies (V-Mg) and neutral oxygen vacancies (V-O) in the material, and we found that a charge transfer can occur between the N-impurity states and these intrinsic defects. In particular, a substitutional nitrogen behaves as all electron donor in the presence of V-Mg, and as an electron acceptor in the presence of V-O centers. The Occurrence of the internal charge transfer may alter the magnetic properties of the material. |
| Databáze: | OpenAIRE |
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