Magnetism of α- and β-TDAE-C60

alpha-TDAE-C-60 is a purely organic soft ferromagnet with T-C approximate to 16 K: The mechanism of the ferromagnetism was recently proposed to be antiferro-orbital-ordering of Jahn-Teller distorted C-60(-) (Mizoguchi et al., Phys. Rev. B 63 ( 2001) 040417(R)), which reproduces the pressure dependence of T-C: Further, [2 + 2]-polymerized beta-TDAE-C-60 was found under pressure more than 9 k bar; where the spin on TDAE missing in alpha-phase revives. This paper reports on the effect of uniaxial strain to T-C, an increase up to 17.5 K, and on the nature of the polymeric beta-TDAE-C-60: (C) 2003 Elsevier B.V. All rights reserved.