Microwave Conductivity of the Soft Ferromagnet (TDAE)-C60

(Tetrakisdimethylaminoethylene)-${\mathrm{C}}_{60}$ was the first fullerene charge transfer complex with a transition into a soft ferromagnetic low temperature phase at 16 K. The origin of the low temperature phase in (TDAE)-${\mathrm{C}}_{60}$ is still a subject of discussion. To unravel the real nature of the ferromagnetic ground state we will present measurements of the conductivity in (TDAE)-${\mathrm{C}}_{60}$ for the first time. The conductivity is of the order of ${10}^{-4\mathrm{}}$ S/cm at room temperature and the temperature dependence is clearly nonmetallic. This contradicts the assumption that (TDAE)-${\mathrm{C}}_{60}$ is a ferromagnetic metal.