Physical properties and thermal stability of zirconium platinum nitride thin films

Transition metal nitrides (TMNs) are a peculiar class of interstitial compounds, where nitrogen forms a nonmetallic sublattice on the interstitial sites of the crystal .

These materials can assume metallic, ionic, and covalent behavior at the same time because of their unique combination of a finite density of states ( DOS ) at the Fermi energy, wave-function overlap, and electrostatic interactions between the metallic and nonmet metallic sub lattice.

ZrPtN system shows promise for functional enhancements in catalytic properties by the incorporation of a highly active metal like platinum.

Figure 1(a ) depicts the optimized crystal structure of ZrN and Zr16Pt6N6 calculated with Quantum Espresso .

At low Pt concentrations ( %), the film maintains the rock salt structure typical of ZRN (green peak) and simply incorporates Pt as a defect.

With the addition of Pt atoms, the unit cell expands to 28 atoms/cell and forms a stable diamond-like structure.

At larger concentrations of Pt, the ZrPtxNy peak appears and the material shifts to a different cubic unit cell.

In films annealed at 955 C , exsolved Pt particles form on the surface as demonstrated in the 1% Pt films.

Pt3Zr structures form highly stable bonds,27 which drive preferential incorporation of Pt over ZrO bonds.

Pt-rich nuclei lower the film's average hardness and create localized opportunities for deformation.