Effect of oxygen content and superconductivity on the nonvolatile resistive switching in YBa2Cu3O6+x/Nb-doped SrTiO3 heterojunctions

The authors report on the resistive switching effect in YBa2Cu3O6+x/Nb-doped SrTiO3 heterojunctions. The current-voltage curves of these heterojunctions show hysteresis, which increases with decreasing temperature and oxygen content. Multiresistance states are realized by voltage pulses with different amplitudes. The relaxation of the junction current after switching follows the Curie-Von Schweidler law. More interestingly, the resistance of the low resistance state for the heterojunction shows a metallic behavior with a remarkable drop at T-c. The results were discussed in terms of the trapping-detrapping process via oxygen vacancies near the interface of the heterojunction and the conducting filaments through the junction barrier.