Andersen Group | El.-Phon. | QMC | C60 | GW | Resistivity saturation |
Orientational interaction |
Based on the tight-binding
parameters obtained
from the band-structure calculations, the hopping energy between the
molecules has been studied. This energy shows a strong dependence
on the orientations of the C60 molecules
(
Phys. Rev. Lett. 67, 3002 (1991)). Based on this,
an Ising model (Phys. Rev. Lett.
70, 4142 (1993);
I.I. Mazin et. al, Solid State Commun. 91, 497 (1994);
Springer Series in Solid State
Sciences 117, Springer, Berlin, 1993, p. 211.) was developed for
A3C60, where the alkali ions
restrict the C60 orientations and make two
different orientations particular favorable. The interaction in
this Ising model is antiferromagnetic and of the order J~100 K.
The study of the phonon line shape
seen in Raman scattering
provides some support for a local "antiferromagnetic" correlation.
Such support is also obtained from neutron scattering (S. Teslic, T. Egami,
and J.E. Fischer, Phys. Rev. B
Andersen Group |
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