title: Magnetic properties and crystal structure of solvent-free Sc@C82 metallofullerene microcrystals.
abstract: Magnetic properties of solvent-free crystals of the endohedral Sc@C82 are investigated by SQUID and X-ray powder diffraction. We find that the crystal is a paramagnet and the magnetic susceptibility decreases from 150 K with evidence of antiferromagnetic-like interactions by slow cooling. X-ray crystal analysis reveals the presence of a phase transition at 150 K, which is attributed to an orientational ordering transition of the fullerene molecules. At low temperatures we find a magnetic metastable state that can be controlled by the cooling rate. The metastable state can be formed by rapid cooling. The direction of Sc@C82 molecular axis in the crystals is disordered in the metastable state, and the susceptibility is higher than that in the slow cooling case at low temperature.
authors.affiliation: Department of Chemistry & Institute for Advanced Research, Nagoya University, Nagoya 464-8602, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Wataru
authors.initials: W
authors.lastname: Fujita
authors.forename: Toshiya
authors.initials: T
authors.lastname: Okazaki
authors.forename: Toshiki
authors.initials: T
authors.lastname: Sugai
authors.forename: Kunio
authors.initials: K
authors.lastname: Awaga
authors.forename: Eiji
authors.initials: E
authors.lastname: Nishibori
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.forename: Makoto
authors.initials: M
authors.lastname: Sakata
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara