Orientational disorder in solvent-free solid c70.
The high-temperature structure of solvent-free C(70) has been determined with high-resolution x-ray powder difraction and electron microscopy. Samples crystallized from solution form hexagonal close-packed crystals that retain an appreciable amount of residual toluene, even after prolonged heating. Samples prepared by sublimation, which contain no detectable solvent, are primarily face-centered cubic with some admixture of a hexagonal phase. The relative volume of the hexagonal phase can be further reduced by annealing. The structures of both phases are described by a model of complete orientational disorder. The cubic phase contains an appreciable density of stacking faults along the [111] direction.
Vaughan
G B
GB
Heiey
P A
PA
Luzzi
D E
DE
Ricketts-Foot
D A
DA
McGhie
A R
AR
Fischer
J E
JE
Hui
Y W
YW
Smith
A L
AL
Cox
D E
DE
Romanow
W J
WJ
Allen
B H
BH
Coustel
N
N
McCauley
J P
JP
Smith
A B
AB