Preparation and Characterization of Iron Manganese Carbide by Reaction of the Oxides and Carbon in Nitrogen

Abstract Fe2O3, Mn2O3, and their mixtures are reduced by carbon in nitrogen. The product depends on manganese loading. A cohenite Fe3C type phase is stabilized by substituting manganese into the lattice. A single phase cohenite phase solid solution Fe3-xMnxC is prepared for 20-50% manganese loading, and a Fe7C3 type phase can be obtained with manganese loading of 65-80%. The nitrogen participates in the reduction of the manganese-rich oxide mixtures. A manganese carbonitride is obtained by heating the mixture of Mn2O3 and carbon in nitrogen. The composition of the new compound is analyzed as Mn2C0.60N0.21 and it has a hexagonal structure with a0 = 4.778 A and c0 = 4.486 A.