The Laser Ablation Production of Platinum Nitride and its Possible Structure

TL;DR

This study reports the laser ablation synthesis of platinum nitride, revealing nitrogen's interstitial placement as N-units at low concentrations, challenging previous assumptions of N2-unit configurations in platinum nitride.

Contribution

It provides new spectroscopic and computational evidence on nitrogen site configurations in platinum nitride, clarifying the structure at various compositions.

Findings

Nitrogen exists as N-units in interstitial sites at low concentrations.

N2-unit configuration appears only at high nitrogen concentrations.

Density functional calculations support the experimental site assignments.

Abstract

The synthesis of platinum nitride by the laser ablation method is reported. The spectroscopic results show that nitrogen is in interstitial sites of platinum as N-units, contradicting the accepted configuration for PtN2 where it is as N2-units. To elucidate this point we did density functional calculations to correlate composition with nitrogen sites. For dilute nitrogen concentrations, x < 0.2, nitrogen would be in six-fold coordinated sites (octahedral interstices) as N-units. For 0.2 < x < 1.5, nitrogen would be in tetrahedral interstices as N-units. Only for x > 1.5 the N2-configuration in octahedral sites is attained.