Influence of Li ions on memristor properties of capacitor structures based on nanocomposites (Co$_{50}$Fe$_{50}$)$_x$(LiNbO$_3$)$_{100-x}$

The paper reveals the influence of Li, B and the composition of metal contacts on the processes of resistive switching in memristive structures M/NC/D/M. After field exposure in structures Cu/(Co$_{50}$Fe$_{50}$)$_x$(LiNbO$_3$)$_{100-x}$/s-LiNbO$_3$/Cu/ситалл, Cu/(Co$_{50}$Fe$_{50}$)$_x$(LiNbO$_3$)$_{100-x}$/d-LiNbO$_3$/Cu/sitall and Cu/(Co$_{40}$Fe$_{40}$B$_{20}$)$_x$(SiO$_2$)$_{100-x}$/d LiNbO$_3$/Cu/sitall at $x <$ 13 was detected a residual voltage (up to 16 mV) due to the electromigration of Li ions, that leading to a “reversible” type of VAC hysteresis and instability of the time dependencies of induced resistive states. In the structures of Cu/(Co$_{40}$Fe$_{40}$B$_{20}$)$_x$(LiNbO$_3$)$_{100-x}$/s-LiNbO$_3$/Cu/sitall, Cr/Cu/Cr/(Co$_{40}$Fe$_{40}$B$_{20}$)$_x$(LiNbO$_3$)$_{100-x}$/s-LiNbO$_3$/Cr/Cu/Cr/sitall containing B, the residual voltage is reduced by formation of chemical compounds B with percolated Li atoms. When limiting the electromigration of Li ions, the main mechanism of resistive switching is the processes of electromigration of oxygen vacancies in the dielectric oxide layer. Suppression of residual voltage in the Cr/Cu/Cr/(Co$_{50}$Fe$_{50}$)$_x$(LiNbO$_3$)$_{100-x}$/s-LiNbO$_3$/Cr/Cu/Cr/sitall structure due to the introduction of a Cr buffer layer that does not dissolve Li leads to the absence of bipolar resistive switching in these structures.