OsN2: Crystal structure and electronic properties
Résumé
Osmium nitride belongs to a family of nitrides synthesized recently at high pressures from their parent elements. Here we show, based on first-principles calculations, that the crystal structure of osmium nitride is isostructural to marcasite. Excellent agreement is obtained between the authors' results and x-ray, Raman, and compressibility measurements. In the OsN2 marcasite structure single-bonded N2 units occupy the interstitial sites of the Os close-packed lattice, giving rise to a metallic compound. A comparison between the formation energies of OsN2 and PtN2 explains the similar thermodynamic conditions of formation reported experimentally for the two compounds.
Mots clés
- Other nonmetallic inorganics
- osmium compounds
- crystal structure
- ab initio calculations
- compressibility
- Fermi level
- electronic density of states
- Other inorganic compounds
- Point defects and defect clusters
- interstitials
- Deformation and plasticity
- Deformation plasticity and creep
- Inorganic compounds
- 71.20.Ps
- 61.72.Ji
- 78.30.Hv
- 62.20.Fe
- 81.40.Lm
- 61.66.Fn
- Raman spectra
