Nuclear Magnetic Resonance (NMR) and Electron Spin Resonance (ESR) Characterization of Sublimed C₆₀ Solid

Abstract

Two kinds of electron spin resonance (ESR) signals were found in sublimed 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 sublimation leads to a C 60 solid which does not show any detectable ESR signal. 13 C-nuclear magnetic resonance (NMR) study showed that the sublimed solid is much more homogeneous than the solution-grown solids, and that C 60 orientational ordering transition around 262 K is a first-order phase transition.