L. Marques et al., "Debye-Scherrer ellipses" from 3D fullerene polymers: An anisotropic pressure memory signature, SCIENCE, 283(5408), 1999, pp. 1720-1723
High-pressure studies on fullerenes have previously shown the existence of
one- and two-dimensional (2D) polymerized C-60 structures. Synchrotron radi
ation measurements, performed on C-60 samples quenched from 13 gigapascals
and 820 kelvin, yield unambiguous proof for the existence of a three-dimens
ional (3D) polymerized C-60 derivative. Moreover, unusual ellipsoidal Debye
-Scherrer diffraction patterns are observed, which shows that the giant ani
sotropic deformation induced by the nonhydrostatic compression is retained
in the quenched samples. The multiple bonding possibilities of the highly s
ymmetrical C-60 allow the retention (down to ambient pressure) of the defor
mation, a phenomenon reported previously only under high pressure.