The electronic structure of tantalum (oxy)nitrides TaON and Ta3N5
| Autor: | C. M. Fang, E. Orhan, G. A. de Wijs, H. T. Hintzen, R. A. de Groot, R. Marchand, J.-Y. Saillard, G. de With |
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| Přispěvatelé: | Zernike Institute for Advanced Materials, Materials and Interface Chemistry, Inorganic Materials & Catalysis |
| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
Band gap
Chemistry Neutron diffraction Ab initio Tantalum chemistry.chemical_element General Chemistry Electronic structure Molecular physics Pseudopotential Computational chemistry Materials Chemistry ComputingMethodologies_DOCUMENTANDTEXTPROCESSING Density functional theory Electronic band structure GeneralLiterature_REFERENCE(e.g. dictionaries encyclopedias glossaries) |
| Zdroj: | Journal of Materials Chemistry, 11(4), 1248-1252. ROYAL SOC CHEMISTRY Journal of Materials Chemistry, 11(4), 1248-1252. Royal Society of Chemistry |
| ISSN: | 0959-9428 |
| Popis: | Detailed results of ab initio band structure calculations for tantalum (oxy)nitrides (TaON and Ta3N5) are reported. The calculations are performed within the framework of density functional theory (DFT). We compare results obtained with the molecular dynamics pseudopotential (PP) approach of the Vienna Ab initio Simulation Program (VASP) and the Full Potential Linearized Augmented Plane Waves method (FP-LAPW) using the WIEN97 program. In agreement with neutron diffraction measurements, we show an ordering of the anions in TaON. The calculations also show that the valence band is composed mainly of the anion 2p orbitals hybridized with Ta 5d states. For TaON the top of the valence band is dominated by N 2p states. The bottom of the conduction band is mainly composed of Ta 5d states. Both TaON and Ta3N5 are semiconductors with calculated indirect band gaps of respectively 1.8 and 1.1 eV (VASP calculations) and 2.0 and 1.2 eV (WIEN97 calculations). Optical diffuse-reflectance spectra show an energy gap of 2.08 eV for Ta3N5. |
| Databáze: | OpenAIRE |
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