Magnetization response and magnetoelectric coupling of Mn-doped BiFeO₃ thin films–microwave-assisted sol–gel approach

Bismuth iron oxide is a promising material that can exhibit ferroelectric and ferromagnetic phenomena simultaneously at room temperature. However, some problems related to bismuth iron oxide include volatile nature of bismuth oxide and large value of leakage current. Present study is an attempt to address these problems by doping manganese (Mn) in BiFeO₃ with varying Mn concentration from 1 to 5wt%. The sols of undoped and doped BiFeO₃ are processed by microwave-assisted sol–gel method at a power of 720 W. These sols are spin deposited on copper substrates and annealing was performed at temperature of 350 °C. XRD analysis shows the incorporation of doping ions without altering the rhombohedral structure. Crystallite size is found to be less than cycloidal spin structure. Ferromagnetic nature with high value of saturation magnetization was observed in doped samples. The microwave synthesized thin films show normal and anomalous behavior, i.e. U-shaped dielectric response. The dominant role of grain boundaries is observed from Cole–Cole plots. ME coupling is observed for the samples that makes this material an interesting system to be considered in magneto electric applications.