The dynamic properties of pristine C60 and C70 are reviewed, emphasizing the results of the ZF- and ALC-μ+SR techniques. In C60, the fcc → sc transition is accompanied by a change in the dynamics from isotropic reorientational to quasi-random jump motion between nearly-degenerate orientations. C70 is frozen on a timescale of 30 ns up to 170 K. At higher temperatures, the motion is found to be complex, consisting of a uniaxial rotation part together with a nutational or jumping motion of the unique axis. Anisotropy on the 30 ns timescale persists to 370 K, well into the fcc phase. The ZF-μ+SR technique has been also employed to study the magnetic properties of fullerides. In the organic salt (TDAE)C60, spontaneous magnetic order is directly observed below a Curie temperature of 16.1 K, higher than any other organic material. In the quasi-one-dimensional conductor CsC60, static magnetic order of a random nature is observed to develop in the vicinity of the metal-insulator transition at 30 K with no direct evidence of long range order present.
|Number of pages||11|
|Publication status||Published - 1997 Dec 1|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Condensed Matter Physics
- Physical and Theoretical Chemistry