Density Functional Theory Approach to the Study of the Structural Stability of Nitrides of Iron and Nickel

Nitrides of transition metals such as iron and nickel are known to possess excellent properties relevant for technological applications. Among these, FeNhas been synthesized in zinc blende face centered cubic (�43��) crystal structure while NiN has not been synthesized yet. Literature search revealed that hexagonal close packed and primitive tetragonal structures of these compounds have not been investigated to ascertain their preference.Therefore, the structural stability of Zinc blende face centered cubic, hexagonal closed packed and primitive tetragonal crystal structures of the compounds were investigated in this study.Generalized gradient approximation of Perdew-Burke-Ernzerhof revised for solids (GGA-PBEsol) as implemented in Quantum espresso package was used based on density functional theory for the computation. The results revealed that FeN and NiNcompounds prefer Zinc blende face centered cubic crystal structure as their equilibrium lattice parameters occurred at the least equilibrium minimum energies in this structure. The lattice parameters of FeN and NiN compounds in thezinc blende FCC crystal structure were computed to be 4.232 Šand 4.324 Šrespectively in agreement with experiment and previous computations.The preference of zinc blende FCC crystal structure by these compounds imply they may possess highly directional covalent bonds that prefer a tetrahedral arrangement of atoms, thus forming good binary semiconductor compounds. Therefore, these compounds have high possibility of been synthesized in zinc blende FCC crystal structure