Chromium nitride

Chromium nitride is a chemical compound of chromium and nitrogen with the formula 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:^[2] 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, Cr₂N.

Chromium nitride

Chromium nitride
Names
IUPAC name Chromium nitride
Other names Chromium(III) nitride
Identifiers
CAS Number	24094-93-7 Y
3D model (JSmol)	Interactive image
ChemSpider	81581 Y
ECHA InfoCard	100.041.819
EC Number	246-016-3
PubChem CID	90362
UNII	W46I1HZ91F Y
InChI InChI=1S/Cr.N Y Key: CXOWYMLTGOFURZ-UHFFFAOYSA-N Y InChI=1/Cr.N/rCrN/c1-2 Key: CXOWYMLTGOFURZ-NIYUYJRQAK
SMILES [Cr]#N
Properties
Chemical formula	CrN
Molar mass	66.003 g/mol
Appearance	Black powder
Density	5.9 g/cm3 [1]
Melting point	1770 ˚C (decomp.)[2]
Solubility in water	Insoluble[3]
Thermochemistry
Std molar entropy (S⦵298)	37.75 J K−1 mol−1 [4]
Std enthalpy of formation (ΔfH⦵298)	−117.15 kJ/mol [4]
Hazards
Flash point	Non-flammable
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 1 mg/m3[5]
REL (Recommended)	TWA 0.5 mg/m3[5]
IDLH (Immediate danger)	250 mg/m3[5]
Related compounds
Related compounds	Dichromium nitride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Synthesis

Chromium(III) nitride can be prepared by direct combination of chromium and nitrogen at 800 °C:

2 Cr + N
₂ → 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.^[6] 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.^[7]

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.^[8][9] 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.^[10][11][12]

Natural occurrence

Though rare, carlsbergite - the natural form of chromium nitride - occurs in some meteorites.^[13]