Platinum nitride Pt4N compound: first principles investigations

This paper highlights the application of first principle calculations based on density functional theory calculations to study platinum nitride properties of the formula Pt₄N. It is well known that technological properties of surface layers may be significantly modified by the use of nitrides. In fact, the structural and thermodynamical stabilities of Pt₄N compound have been established first and the elastic and electronic properties have been investigated second. Between seven crystallographic phases studied, the cubic structure with space group P43m (No. 215) was found to be the most structurally and thermodynamically stable one. The structural parameters, bulk moduli and their first pressure derivatives were determined for all studied structures. Practically, all the studied phases were found to be nonmagnetic; this is due to the fact that the platinum compound is non-magnetic. For the ground-state of Pt₄N-structure, all crystalline elastic constants (in the equilibrium and under hydrostatic pressure), the Young moduli, as well as homogenized polycrystalline elastic moduli (obtained by different homogenization methods) were predicted. The ground-state structure of the Pt₄N compound is found mechanically stable and considered to be ductile.