The conductivity and the diamagnetic response of the graphene-like carbon films in the 80 – 120 K temperature range

The paper presents the results of conductivity and diamagnetic response studies in natural carbon films in the temperature range 77–220 K. The behavior of the current-voltage characteristic of carbon films containing graphene-like fragments was studied by nanosecond voltammetry. It is established that when the critical temperature is reached, the sample resistance increases sharply with the simultaneous disappearance of diamagnetism. Was proposed possible mechanism of high-temperature superconductivity based on synchronization of negative-U centres presumably exists in the carbon structure under study. (paper)