Elastic Properties and Electronic Properties of M(x)N(y) (M = Ti, Zr) from First Principles Calculations

The elastic properties and electronic properties of M(x)N(y) (M = Ti, Zr) TiN, Ti(2)N, Zr(3)N(4), ZrN with different structures have been investigated using density functional theory. Through the calculation of the elastic constants, it was found that all of these structures meet the mechanical stability except for ZrN with space group P6(3)mc. Their mechanical properties are studied by a comparison of various parameters. The stiffness of TiN is larger than that of ZrN with space group Fm [Formula: see text] m. Ti(2)N’s stiffness with space group I4(1)/amdz is larger than Ti(2)N with space group P4(2)/mnm. Zr(3)N(4)’s stiffness with space group Pnam is largest in three structures of Zr(3)N(4). TiN, Ti(2)N and ZrN are non-central force, Zr(3)N(4) is central force. TiN and ZrN with space group Fm [Formula: see text] m are brittle, and TiN is brittler than ZrN with space group Fm [Formula: see text] m. The two kinds of Ti(2)N are brittle and Ti(2)N with space group I4(1)/amdz is larger. Three structures of Zr(3)N(4) are tough and Zr(3)N(4 )with space group I [Formula: see text] 3d is the toughest. Meanwhile, the electronic properties of TiN, Ti(2)N, Zr(3)N(4) and ZrN were calculated, possible superconducting properties of the studied materials were predicted.