Ferromagnetic versus molecular ordering in C_60 charge transfer complexes

摘要

(TDAE)C_60 (TDAE, tetrakis (dimethylamino) ethylene) was the first and is so far the only C_60 charge transfer complex, which exhibits molecualr ferromagnetism with a Curie temperature of about 16 K. Though extensively studied a convincing access to the origin of the low-temperature phase is still missing. Three, mechanisms for the ferromagnetism will be compared: the classical Heisenberg ferrmomagnet, configuration interaction and spin polarization. The role of molecular ordering and of the Jahn-Teller distortion of C_60 will be discussed.