Abstract
Single crystals of the endohedral have been investigated by ESR, SQUID, and optical absorption measurements. We find that the crystal is a localized paramagnet at room temperature with evidence of strong antiferromagnetic interactions ESR spectroscopy reveals evidence of a phase transition at 150 K, that we assign to be an orientational ordering transition of the fullerene molecules. Furthermore, at low temperatures we find a magnetic bistability that can be controlled by the cooling rate. Investigations of reveal evidence of similar bistability and hence we postulate that it is a common phenomena in these endohedrals.
- Received 1 June 2000
DOI:https://doi.org/10.1103/PhysRevB.62.8592
©2000 American Physical Society