Erbium nitride is a binary inorganic compound of erbium and nitrogen with the chemical formula .
The compound forms black powder. Chemically, ErN is more reactive and easily degraded in the air. High humidity causes ErN to hydrolyze, forming and ammonia.
ErN is known for its magnetic and optical properties.
The compound may be incorporated into III-nitride semiconductors in order to create new functional materials for optoelectronic and spintronic devices.