Influence of gamma irradiation on electrophysical properties of onion-like carbon

Temperature dependence of the conductivity of onion-like carbon (OLC) was investigated before and after gamma irradiation. It is found that the temperature dependence of the conductivity is described by the mechanism of variable range hopping conductivity (VRHC). The density of states on Fermi level N(EF) is estimated on slope angle of curves a(7) in coordinates In[s(T)/s293] - T-1/2. The gamma irradiation leads to the increase N (EF) for OLC prepared by vacuum annealing of nanodiamond (ND) particles at temperatures 1400 K, 1650 K and to the decrease N(EF) for OLC produced by the annealing ND at temperatures 1850 K.