EPR investigation of N@C₇₀ in polycrystalline C₇₀ and single wall carbon nanotubes

Abstract

Using multi frequency electron paramagnetic resonance (EPR) it was possible to determine the inherent fine structure (FS) interaction of nitrogen encapsulated in a C₇₀ cage. Confinement of N@C₇₀ in single wall carbon nanotubes (SWNT) of rather wide diameter does not significantly influence this value. The transition between isotropic molecular tumbling and immobilization was found to occur at about 170 K in both matrices, indicating that the hindrance potential is quite small in both cases.

Keywords:

• Single wall carbon nanotubes
• N@C₇₀
• EPR

Acknowledgements

We thank K. Hata for the gracious supply of CVD ‘super-growth’ SWNT samples. Financial support by the ‘Deutsche Forschungsgemeinschaft’ (grant Di182/23) is gratefully acknowledged.