Chromium nitride is a chemical compound of

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

and nitrogen with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...

CrN. It is very hard, and is extremely resistant to corrosion. It is an interstitial compound, with nitrogen atoms occupying the octahedral holes in the chromium lattice: as such, it is not strictly a chromium(III) compound nor does it contain nitride ions (N³⁻). Chromium forms a second interstitial nitride,

dichromium nitride Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hard ...

, Cr₂N.

Synthesis

Chromium(III) nitride can be prepared by direct combination of

and nitrogen at 800 °C: :2 Cr + → 2 CrN It can also synthesize by Physical Vapour Deposition technique such as Cathodic arc deposition.

Applications

CrN is used as a coating material for corrosion resistance and in metal forming and plastic moulding applications. CrN is often used on medical implants and tools. CrN is also a valuable component in advanced multicomponent coating systems, such as CrAlN, for hard, wear-resistant applications on cutting tools.

Magnetism

The fundamental materials physics of CrN, giving rise to its favorable properties, has been debated recently in high-profile scientific journals such as Nature Materials. In particular, the importance of magnetism in both the low temperature and the high temperature phases has been demonstrated by means of quantum mechanical calculations of the electronic structure of the compound.

Natural occurrence

Though rare,

carlsbergite Carlsbergite is a nitride mineral that has the chemical formula CrN, or chromium nitride. It is named after the Carlsberg Foundation which backed the recovery of the Agpalilik fragment of the Cape York meteorite in which the mineral was first des ...

- the natural form of chromium nitride - occurs in some meteorites.

References

{{Nitrides Chromium(III) compounds Nitrides Rock salt crystal structure Coatings