Formation of iodine-doped C₆₀ whiskers by the use of liquid–liquid interfacial precipitation method

Iodine-doped whiskers of C₆₀ (I–C₆₀ whiskers) with diameters ranging from submicrometers to micrometers and lengths longer than 100 μm were successfully obtained by the use of the liquid–liquid interfacial precipitation method. Transmission electron microscopy observations showed that the I–C₆₀ whiskers were single crystalline and had a growth axis parallel to the close-packed direction of C₆₀ molecules and expanded (002) lattice planes indicative of the intercalation of iodine and oxygen atoms between the (002) planes of a body-centered-tetragonal crystal system. The I–C₆₀ whiskers showed nonlinear I-V curves. The electrical resistivity of the I–C₆₀ whiskers was more than three orders of magnitude lower than that of pristine face-centered-cubic C₆₀ crystals.