Great ferroelectric properties and narrow bandgaps of BiFeO3 thin films by (Mg, Mn) modifying

High-quality modified BiFe1-2xMgxMnxO3 (BFMMO-x, x = 0-5 mol%) films were successfully prepared via the sol-gel method . The influence of (Mg, Mn) doping amounts on the crystal structure, oxygen vacancy content, leakage mechanism and optical , ferroelectric and electrochemical properties of the BFMMO films was investi-gated. A l l samples exhibited a pure perovskite phase and successf u l doping of the (Mg, Mn) at the Fe site was achieved. As the stoichiometric ratio increased, the structural distortion of the octahedra increased , resulting in the formation of homogeneous microstructures. XPS measurements illustrated that the replacement of Fe3+ with Mn and Mg ions effectively suppressed the generation of oxygen defects and increased the concentration of Fe3+ ions of the perovskite lattice. A high spontaneous polarization P-r (214.8 mu C/cm(2)) delta P (410.5 mu C/cm(2)) and low leakage (1.5 x 10(-8) A/cm(2)) as well as a good dielectric constant (388.0) and loss (0.017) were simultaneously attained in the BFMMO-4 thin film. A significant widening in the visible absorption range and a decrease in the bandgap were observed from 2.19 to 1.82 eV. By simultaneously introducin g Mg and Mn into the BFO, enabling both a higher polarization and narrower bandgap, a novel method for improving the performance of BFO-based devices was achieved .

Automated summary

High-quality modified BiFe1-2xMgxMnxO3 (BFMMO-x, x=0-5 mol%) films were prepared via the sol-gel method, and the influence of (Mg, Mn) doping on the properties of BFMMO films was investigated. The results showed that doping (Mg, Mn) effectively improved the structural stability, dielectric properties, and optical characteristics of BFMMO films.