Effects of monopolar resistive switching in thin diamond-like carbon layers

The current-voltage characteristics have been studied for Pt/diamond-like C/Pt structures based on thin ($20$ nm) diamond-like carbon layers, in which the ratio between carbon phases with $sp^2$ and $sp^3$ hybridization is controlled by the growth conditions of the layers by the high-frequency diode sputtering method. The effects of resistive switching from the initial high-resistive state to a low-resistive one at an applied voltage of $V\sim 3$ V and reverse switching at $V\sim 0$ V are detected. These effects are symmetric with respect to change in voltage polarity and are explained by the change in the hybridization type of local carbon regions, which causes switching from the high- to low-resistive state in strong ($\sim10^6$ V/cm) fields because of $sp^3\to sp^2$ transitions and reverse switching in the absence of the field. The high-to-low resistance ratio reaches $\sim 50$.