NUCLEAR-MAGNETIC-RESONANCE (NMR) AND ELECTRON-SPIN-RESONANCE (ESR) CHARACTERIZATION OF SUBLIMED C-60 SOLID

Two kinds of electron spin resonance (ESR) signals were found in subli med carbon-sixty (C-60) solid, one of which is extremely sensitive to air while the other is relatively stable. Although the origin of these signals could not be clarified, it was found that successive sublimat ion leads to a C-60 solid which does not show any detectable ES R sign al. C-13-nuclear magnetic resonance (NM R) study showed that the subli med solid is much more homogeneous than the solution-grown solids, and that C-60 orientational ordering transition around 262 K is a first-o rder phase transition.