Nanoionic transport and electrochemical reactions in resistively switching silicon dioxide

The mobility of copper ions and redox reactions of Cu at the interface with SiO2 being directly attributed to the resistive switching effect have been studied by cyclic voltammetry (CV). The electrode kinetics of the Cuz+/Cu redox reactions were analyzed suggesting the formation of both Cu+ and Cu2+ species. The ion mobility shows an unexpected strong dependence on the ion concentration indicating ion-ion interactions typical for concentrated solution conditions. Based on the standard reduction potentials for Cuz+/Cu we identified partial electrochemical redox reactions during oxidation and reduction. The results contribute to a detailed understanding of the resistive switching effect in Cu/SiO2/Pt cells and provide insight into electrochemically assisted diffusion of metal cations in oxides in general.