The ammoniation of lithium-doped C60 gives rise to (NH3)6LixC60, a system which is chemically expanded while maintaining C60 original cubic symmetry and hence the threefold degeneracy of the C60x- frontier orbitals. Nevertheless, the on-site repulsion U dominates the bandwidth W and, by overcoming the effect of orbital degeneracy, brings to electron localisation. Muon-spin relaxation (μSR) and SQUID magnetometry were used to confirm the presence of a magnetically ordered phase at low temperatures, already reported by Durand and co-workers [Nat. Mater. 2 (2003) 605]. Surprisingly, neither the expected antiferromagnetism nor the even-odd effect on electron band filling were observed down to 2 K.
µSR and SQUID Investigation of Ammoniated Lithium Fullerides / Ricco', Mauro; Belli, Matteo; Shiroka, T; Pontiroli, Daniele; Pagliari, M; Gianferrari, F; Gorreri, A.. - In: PHYSICA. B, CONDENSED MATTER. - ISSN 0921-4526. - 374-375:(2006), pp. 255-258.
µSR and SQUID Investigation of Ammoniated Lithium Fullerides
RICCO', Mauro;BELLI, Matteo;PONTIROLI, Daniele;
2006-01-01
Abstract
The ammoniation of lithium-doped C60 gives rise to (NH3)6LixC60, a system which is chemically expanded while maintaining C60 original cubic symmetry and hence the threefold degeneracy of the C60x- frontier orbitals. Nevertheless, the on-site repulsion U dominates the bandwidth W and, by overcoming the effect of orbital degeneracy, brings to electron localisation. Muon-spin relaxation (μSR) and SQUID magnetometry were used to confirm the presence of a magnetically ordered phase at low temperatures, already reported by Durand and co-workers [Nat. Mater. 2 (2003) 605]. Surprisingly, neither the expected antiferromagnetism nor the even-odd effect on electron band filling were observed down to 2 K.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
