Magnetic fullerenes inside single-wall carbon nanotubes
  C59N magnetic fullerenes were formed inside single-wall carbon nanotubes by vacuum annealing functionalized C59N molecules encapsulated inside the tubes. A hindered, anisotropic rotation of C59N was deduced from the temperature dependence of the electron spin resonance spectra near room temperature. Shortening of spin-lattice relaxation time, T_1, of C59N indicates a reversible charge transfer toward the host nanotubes above $\sim 350$ K. Bound C59N-C60 heterodimers are formed at lower temperatures when C60 is co-encapsulated with the functionalized C59N. In the 10-300 K range, T_1 of the heterodimer shows a relaxation dominated by the conduction electrons on the nanotubes. 
F. Simon, H. Kuzmany, B. Nafradi, T. Feher, L. Forro, F. Fulop, A.   Janossy, L. Korecz, A. Rockenbauer, F. Hauke, and A. Hirsch