NMR studies of alkali-doped C[sub 60] polymers

Y. Maniwa
2001 AIP Conference Proceedings  
23 Na-and 13 C-NMR of NaC 60 heat-treated under high-pressure are presented, and the results are compared with those of Li x C 60 polymers. The 13 C-NMR spectra clearly showed the existence of sp 3 carbon atoms, evidencing for the transformation to the C 60 polymer phase. The spin-lattice relaxation time, T 1 , of 13 C-NMR suggested an electron localization effect, and the electronic density of states at the Fermi level at 4.2 K was estimated to be smaller than 0.6 states/eV/C 60 /spin, which
more » ... C 60 /spin, which is smaller than 1/10 of that of a superconducting K 3 C 60 . It was also shown that the Na atoms are jumping among at least two different sites in the cavities of C 60 -polymerized network above ~250K. FIGURE 1. Proposed structures for AC 60 (left) and A 4 C 60 (right) polymers. The 13 C NMR spectra confirmed these structures for LiC 60 , NaC 60 and Li 4 C 60 .
doi:10.1063/1.1420147 fatcat:dunb5iljw5cahgm4ekv35b7onu