Resistive switching and magnetic behavior of Bi0.8Ba0.2FeO3/SrRuO3/SrTiO3 films: role of thickness-dependent strain

摘要

The thickness-dependent resistive switching and magnetic behavior of Bi0.8Ba0.2FeO3/SRO/STO (1 0 0) films have been studied in the context of strain modifications introduced by varying the film thickness. Generation of misfit dislocation results in strain relaxation with an increase in film thickness. All films (50, 100 and 200 nm) show hysteresis in I-V behavior at room temperature with applied voltage V-max = +/- 5 V. Fitting of I-V data suggests that trap-controlled SCLC governs the conduction in HRS in the 50 nm film while in the 100 nm and 200 nm films, the charge transport mechanism is ohmic-type throughout the applied field. The ON/OFF switching ratio and current retention performance decrease with an increase in film thickness, suggesting that substrate-induced strain and interface modifications play an important role in governing the resistive switching mechanism in Bi0.8Ba0.2FeO3 films. A film with lower thickness similar to 50 nm is found to exhibit the highest magnetization which may be attributed to the increase in oxygen vacancies and compressive strain.