Iron monophosphide, FeP

Iron monophosphide, FeP, results when vaporised phosphorus is passed over diferro phosphide at red heat, until no further increase in weight occurs. It has also been prepared by heating phosphorus and iron together at red heat, and also by the action of hydrogen phosphide upon ferric, chloride, ferrous sulphide, or ferrous chloride at red heat.

Heated in air it loses part of its phosphorus, ferric phosphate remaining.