title: Orientational and Magnetic Ordering of Buckyballs in TDAE-C60.
abstract: Spin ordering in the low-temperature magnetic phase is directly linked to the orientational ordering of C(60) molecules in organically doped fullerene derivatives. Electron spin resonance and alternating current susceptometry measurements on tetrakis(dimethylamino)ethylene-C(60) (TDAE-C(60)) (Curie temperature T(c) = 16 kelvin) show a direct coupling between spin and merohedral degrees of freedom. This coupling was experimentally demonstrated by showing that ordering the spins in the magnetic phase imprints a merohedral order on the solid or, conversely, that merohedrally ordering the C(60) molecules influences the spin order at low temperature. The merohedral disorder gives rise to a distribution of pi-lectron exchange interactions between spins on neighboring C(60) molecules, suggesting a microscopic origin for the observed spinglass behavior of the magnetic state.
authors.forename: D
authors.initials: D
authors.lastname: Mihailovic
authors.forename: D
authors.initials: D
authors.lastname: Arcon
authors.forename: P
authors.initials: P
authors.lastname: Venturini
authors.forename: R
authors.initials: R
authors.lastname: Blinc
authors.forename: A
authors.initials: A
authors.lastname: Omerzu
authors.forename: P
authors.initials: P
authors.lastname: Cevc