Resonant photoemission study of the electronic structure of 3 keV nitrogen-implanted tantalum
- Departamento de Fisica Aplicada, Facultad de Ciencias, C-XII, Universidad Autonoma de Madrid, Cantoblanco, 28049-Madrid (Spain)
- LURE, Centre Universitaire Paris-Sud, Bat. 209 D, B.P. 34, 91898 Orsay Cedex (France)
The electronic properties of tantalum nitride thin films grown by 3 keV nitrogen implantation have been studied with resonant photoemission using synchrotron radiation. Resonant photoemission from the valence band was observed when the photon energy was in the neighborhood of the Ta 5p{yields}5d, 5p{yields}6sp and 4f{yields}5d transition energies. The constant initial state curves show multiple resonance maxima that are explained in terms of the Ta 5p{yields}5d, 5p{yields}6sp and 4f{yields}5d photoabsorption mechanisms, the spin-orbit splitting of the Ta 5p and Ta 4f core levels, and the splitting of the N-Ta hybridized unoccupied states by crystal-field interactions. A strong resonance has been observed at the Ta4f{yields}5d transition. Resonant photoemission results suggest a strong hybridization of the Ta 5d and N 2p atomic orbitals along the main feature of the VB (between {approx}3-9 eV) due to the extended nature of Ta orbitals. Occupied vacancy states at {approx}2 eV show a resonance enhancement that supports the Ta character recently predicted for such states by Stampfl and Freeman. Stronger resonances are found for the hybridized Ta 5d-N 2p valence band features lying in the {approx}3-9 eV range, than for the essentially Ta-like ones just below the Fermi level. This suggests that an interatomic recombination mechanism in which N 2p states resonate themselves could also take place.
- OSTI ID:
- 20665057
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 71, Issue 3; Other Information: DOI: 10.1103/PhysRevB.71.035405; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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