A New Potential Superhard Phase of OsN2
Q.Y. Fana, Q. Weib, H.Y. Yanc, M.G. Zhangd, D.Y. Zhange and J.Q. Zhanga
aSchool of Microelectronics, Xidian University, Xi'an 710071, PR China
bSchool of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071, PR China
cCollege of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji 721013, PR China
dDepartment of Physics and information technology, Baoji University of Arts and Science, Baoji 721016, PR China
eSchool of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen Graduate School, Shenzhen 518055, PR China
Received: November 5, 2013
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A new phase of C2/m OsN2 is proposed in this paper. The crystal structure, elasticity and electronic properties of C2/m OsN2 were studied by first-principles calculations. The elastic constants, the elastic moduli (B, G, and E) and Poisson's ratio v of OsN2 have been investigated. From the first-principles calculations, we find that C2/m OsN2 is metallic and mechanically stable. The quasi-harmonic Debye model, using a set of total energy versus molar volume obtained from the first-principles calculations, is applied to the study of the thermal and vibrational effects. The dependence of structural parameters, thermal expansions, heat capacities, Gr√ľneisen parameters and Debye temperatures on the temperature and pressure are obtained in the whole pressure range from 0 to 80 GPa and temperature range from 0 to 800 K as well as compared with available data.

DOI: 10.12693/APhysPolA.126.740
PACS numbers: 62.20.de, 65.40.-b, 62.20.dq