Organic Molecular Soft Ferromagnetism in a Fullerene C 60

The properties of an organic molecular ferromagnet [C 60 TDAE 0.86 ; TDAE is tetrakis(dimethylamino)ethylene] with a Curie temperature T c = 16.1 kelvin are described. The ferromagnetic state shows no remanence, and the temperature dependence of the magnetization below T c does not follow the behavior expected of a conventional ferromagnet. These results are interpreted as a reflection of a three-dimensional system leading to a soft ferromagnet.