742a.    DRAIN, J., AND MICHEL, A.  [Structure and Thermomagnetic Properties of the Cobalt Carbide Co₂C.]  Bull. Soc.Chim., 1951, pp. 547-549.

       By passing CO over Co at 210° Co₂C was formed.  Its structure appears to result from the insertion of C atoms into an orthorhombic, almost compact hexagonal, network of Co atoms.  The insertion gives rise to a series of solid solutions which may deviate from the composition Co₂C.  The carbide Co₂C is transformed under vacuum into a compact hexagonal phase which is a solid solution of C in a-Co, this phase being progressively decarburized by heating to give a pure hexagonal Co.  The gases, H₂, N₂, CO, in accordance with their nature, react upon Co₂C and cause an evolution analogous to that which the hexagonal Ni carbide undergoes under the same conditions.