Magnetic properties of C60 and C70 complexes with tetrakis(dimethylamino) ethylene (TDAE) have been studied based on the measurements of the Faraday-balance magnetization and the electron-spin resonance (ESR). It has been found that both TDAE-C60 and TDAE-C70 possess about one radical spin per fullerene molecule. TDAE-C60 has been confirmed to show a ferromagnetic-type transition at Tc=16.7-17.5 K. Appearance of a broad and intense ESR signal below Tc for TDAE-C60 suggests that the radical spins in the magnetically ordered state are rather localized on each C60 molecule and are ferromagnetically correlated. On the other hand, TDAE-C70 does not show ferromagnetism at temperatures above 4.5 K.
All Science Journal Classification (ASJC) codes