ORIGIN OF WEAK FERROMAGNETISM IN TDAE-C-60

A mechanism leading to the coexistence of weak ferromagnetism and spin glass behavior in the weak organic ferromagnet TDAE-C-60 is proposed. In view of the non-metallic character of TDAE-C-60, the C-60(-)-C-60( -) intra-chain coupling along the c-axis as well as the inter-chain C- 60(-)-C-60(-) are assumed to be of antiferromagnetic nature, if the sp in density on the TDAE' ion is inhomogeneously distributed the TDAE' m ediated super-exchange leads to a ferromagnetic coupling between C-60( -) ions on different chains. This leads to a Dzyaloshinsky-Moriya type coupling responsible for the spin-canting and a non-zero spontaneous magnetization. Other models like three dimensional ferromagnetic orbit al ordering of Jahn-Teller distorted C-60 molecules are discussed as w ell.