Structural and magnetic properties of polymerized C<Subscript>60</Subscript> with Fe

We provide evidence that high-pressure high-temperature (2.5 GPa and 1040 K) treatment of mixtures of iron with fullerene powders leads to the complete transformation of iron into iron carbide Fe<Subscript>3</Subscript>C. The comparison of the magnetic properties (Curie temperature and magnetic moment) of the here studied samples and those for the ferromagnetic polymer Rh-C<Subscript>60</Subscript> indicates that the main ferromagnetic signal reported in those samples is due to Fe<Subscript>3</Subscript>C and not related to the ferromagnetism of carbon as originally interpreted. Taking into account the results obtained in this study the original paper on “Magnetic carbon" [Nature <Emphasis Type="Bold">413, 716 (2001)] was recently retracted. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2007