Cubic perovskite-type Mn4C is difficult to prepare for its metastable characteristics. In this work, we have
obtained high-purity Mn4C successfully by using melt-spinning method. The effects of stoichiometry on the
structure and magnetic properties of the samples were studied systematically. We found that x = -0.1 is the
optimum composition for the formation of the cubic perovskite phase in Mn4+xC during rapid quenching. Most
Mn4+xC melt-spun ribbons with x other than -0.1 are composed of Mn23C6, α-Mn, and Mn4C, while the fraction
of different phase in Mn4+xC ribbons varies with x. The Curie temperature of Mn4+xC ribbons increases
slightly with decreasing x, which may affect the lattice parameters of cubic Mn4C and thus the Mn-Mn
exchange interactions. The magnetization of Mn4+xC (x = -0.1 and 0) increases with increasing temperature in
high-temperature region while the onset temperature for such behavior is dependent on the fraction of Mn4C in
the samples.