Novel cm-size free-standing buckypapers of bucky-onions filled with a single-phase of ferromagnetic Fe3C single crystals were serendipitously discovered. These buckypapers are obtained directly in situ as the dominant product of the pyrolysis of ferrocene. Vibrating sample magnetometry also revealed an extremely large coercivity of 0.120 tesla and a saturation magnetization of 41 emu g−1.
