An investigation of structural and electrical transport properties of Y-Mn co-doped Multiferroic BiFeO3 thin films

Polycrystalline BiFeO3 and Bi0.97Y3Fe0.95Mn0.05O3 (BYFMO) thin films were prepared by sol-gel spin coating technique. Structural and electrical properties of both the material were investigated. X-ray diffraction reveals the stable structure of BiFeO3 with the appearance of additional impurity phases after Y-Mn co-doping. Raman spectroscopy analysis indicates structural distortion without changing the structure in the co-doped film. The optical band-gap enhanced up to 2.37eV for Y-Mn co-doped film from the vicinity of parent compounds and can be useful for increasing the photocatalytic activity. Local bipolar resistive switching behavior investigated in Ag/BYFMO/FTO device structure through typical I-V curves. The Ag/BYFMO/FTO device switches from high resistance state (HRS) to low-resistance state (LRS) and finally restores at HRS. The SET and RESET for the studied devices observed at 1.3 V and 2.7 V respectively. Possible mechanisms for resistive switching behavior was explained through space charge limited current (SCLC) conduction mechanism. The oxygen vacancies play a crucial role in switching mechanism, and the switching behavior may be due to formation and rapturing of conducting filament bottom top and the bottom electrode through the dielectric medium.