Oscillation in the electrical conductivity of a thick graphene oxide membrane

Abstract

Because of their unusual fundamental behavior that arises at the molecular scale, the electrical conductivity of stacked graphene oxide (GO) sheets in the presence of external parameters is not adequately understood. Previous studies concentrated on the DC response of thin GO membranes giving their resistive switching properties. Here, we observe anomalous low-frequency (<1 Hz) oscillations in the electrical conductivity of micrometer size GO, which is repeated in a process over and over in an ongoing feedback loop. Such vibrations and their unique trajectories are not only fundamentally important but also have characteristic frequencies that can be directly linked to the formation and destruction of regions with sp2 hybridization. Also, the reported switching time (of the order of seconds) makes our resistive switching system different than all the previously reported systems and introduces a new class of switching phenomena. The observed phenomena improve our understanding of the electrical conductivity of GO membranes and the corresponding microscopic details that pave the way for the promising application of these new observed low-frequency oscillations.