OsN₂: Crystal structure and electronic properties

Javier A. Montoya , Alexander D. Hernandez , Chrystèle Sanloup (1) , Eugene Gregoryanz (1) , Sandro Scandolo (1)

1 IPGP - Institut de Physique du Globe de Paris

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.

Keywords: osmium compounds; crystal structure; ab initio calculations; compressibility; Fermi level; electronic density of states; interstitials; Raman spectra; 61.66.Fn; 81.40.Lm; 62.20.Fe; 78.30.Hv; 61.72.Ji; 71.20.Ps; Inorganic compounds; Deformation plasticity and creep; Deformation and plasticity; Other nonmetallic inorganics; Point defects and defect clusters; Other inorganic compounds

Domains: Sciences of the Universe [physics]

Javier A. Montoya, Alexander D. Hernandez, Chrystèle Sanloup, Eugene Gregoryanz, Sandro Scandolo. OsN₂: Crystal structure and electronic properties. Applied Physics Letters, 2007, 90, ⟨10.1063/1.2430631⟩. ⟨insu-03603202⟩