Modification of dielectric properties of C60, C70 and C84 thin films by oxygen absorption

C60 and higher fullerenes are efficiently produced by the J × B gas-arc method. From the produced soot, C60, C70 and C84 are extracted and purified by the liquid chromatography method. C60, C70 and C84 thin films with a thickness of 1–4 μm are produced by the vacuum sublimation method, and their dielectric properties are investigated. Both the real and imaginary parts of the dielectric constants of C60, C70 and C84 are very high at a low frequency (f = 120 Hz) and they monotonically decrease with time when the films are exposed to air. After sufficient absorption of oxygen, these dielectric constants become almost the same.