Robust resistance switching performance in a Ca3Ti2O7/La0.67Sr0.33MnO3 heterostructure induced by the interface.

Ruddlesden–Popper phase oxides, such as Ca₃Ti₂O₇, have been established as hybrid improper ferroelectrics. However, investigations into Ca₃Ti₂O₇ have primarily concentrated on their structural and ferroelectric properties. In this study, we prepared epitaxial Ca₃Ti₂O₇ thin films via magnetron sputtering. Conducting atomic force microscopy was employed to characterize local current variations under an applied bias voltage. Electron paramagnetic resonance measurements of the Ca₃Ti₂O₇/La_0.67Sr_0.33MnO₃ film were conducted to assess its defect characteristics. Interestingly, the Ca₃Ti₂O₇/La_0.67Sr_0.33MnO₃ stacks exhibited remarkable macroscopic resistance switching, with a resistance on/off ratio reaching 100, alongside robust retention (∼2500 s) and endurance (∼2000 cycles) features. Additionally, density functional theory calculations suggest that the resistance switching is attributable to the interface barrier of the Ca₃Ti₂O₇/La_0.67Sr_0.33MnO₃ interface and the efficacy of space charge limitation. This work proposes an avenue for the utilization of Ruddlesden–Popper phase Ca₃Ti₂O₇ in various applications. [ABSTRACT FROM AUTHOR]