Detailed resistivity measurements were performed, as a function of temperatures in the range of 12 to 300K, on oxygen-loaded C60 films. It was observed that two ordering phase transitions (i.e., To = 260K and Tg = 90K) were present in ρ(T), which, in addition, depended strongly upon the oxygen content. A decrease in both ordering temperatures with increasing oxygen concentration was found. The mechanisms of oxygen diffusion were greatly enhanced in the ordered phase on heating. Finally, the transition to a glassy state at Tg was detected as a point of reversibility of the resistivity curve as a function of temperature.

Oxygen Diffusion in C60 Films. Jaime, M., Nunez Regueiro, M.: Applied Physics A, 1995, 60[3], 289-92