Resistive switching of Pt/Nb: SrTiO₃ and La0.7Sr0.3MnO₃/Nb:SrTiO₃ structures

The barrier-type resistive switching (RS) effect has important potential applications in data storage, memristors and artificial intelligence. However, the mechanism of oxygen-ion (Ö) migration that occurs during the RS process is still controversial. In recent years, considerable advances have been achieved in improving the preparation methods of conductive oxides. Due to their structural characteristics, conductive oxides usually contain oxygen vacancies (V 0 ), which provide suitable conditions for the migration of Ö in the RS process. Based on this, here, a conductive-oxide La[Formula: see text]Sr[Formula: see text]MnO 3 (LSMO) film was prepared on an (00[Formula: see text])− oriented Nb:SrTiO 3 (NSTO, 0.7 wt.%) substrate. Furthermore, a Pt/NSTO structure was also prepared for comparison. The RS effect of both heterogeneous structures was studied in pure N 2 , air, and pure O 2 environments. In the N 2 environment, the two structures exhibit a pronounced RS effect, while the intensity of the RS effect is reduced in both air and the O 2 environment. Due to the presence of V 0 in LSMO itself, Ö is more likely to migrate into/out of LSMO under the action of a bias electric field, which causes the LSMO/NSTO structure to be less sensitive to oxygen atmosphere and to exhibit lower Set/Reset voltages than the Pt/NSTO structure. As the interface barrier of Pt/NSTO is higher than that of LSMO/NSTO, the resistance ratio of the high- and low-resistance states is higher under a negative bias voltage. These results provide an experimental reference to select suitable electrodes for the RS effect and study the RS mechanism.