Chromium nitride is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

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 Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

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 Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

. It is an

interstitial compound In materials science, an interstitial defect is a type of point crystallographic defect where an atom of the same or of a different type, occupies an interstitial site in the crystal structure. When the atom is of the same type as those already ...

, 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 In chemistry, a nitride is an inorganic compound of nitrogen. The "nitride" anion, N3- ion, is very elusive but compounds of nitride are numerous, although rarely naturally occuring. Some nitrides have a find applications, such as wear-resistant ...

ions (N³⁻). Chromium forms a second interstitial nitride, dichromium nitride, Cr₂N.

Synthesis

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

and

at 800 °C: :2 Cr + → 2 CrN It can also synthesize by Physical Vapour Deposition technique such as

Cathodic arc deposition {{Short description, Type of physical vapor deposition technique Cathodic arc deposition or Arc-PVD is a physical vapor deposition technique in which an electric arc is used to vaporize material from a cathode target. The vaporized material then co ...

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