Benzene-solvated C60:1H nuclear spin-lattice magnetic relaxation

Crystalline C60.4C6H6 was studied by NMR. Using a saturation-recovery method, the spin-lattice relaxation time, T1, of the protons of benzene was measured as a function of temperature between 4 K and 300 K. The 1H data were fitted by a model where four correlation times are present. They correspond to thermally activated processes which follow an Arrhenius law: the activation energies are, respectively, 60 K, 279 K, 1365 K and 2945 K. All constituents of our system are extremely mobile and no structural phase transitions are observed near 260 K and 90 K as in the case of pure C60 crystals. We have also studied the temperature dependence of the 1H NMR linewidth which narrows with increasing temperature. © 1998 Elsevier Science Ltd.SCOPUS: ar.j