The Ferroelectric and Magnetic Properties of Sol-Gel-Derived (Bi $_{0.85}$ Eu $_{0.15}$ FeO

The Bi_0.85 Eu_0.15 FeO₃ /Bi_3.2 Y_0.8 Ti₃ O₁₂ bilayer thin films were prepared on Pt(111)/Ti/SiO ₂/Si(100) substrates using the sol-gel process and annealed by rapid thermal annealing in various annealing environments (ambient atmosphere and oxygen). The multiferroic/ferroelectric bilayer thin films were composed of 0.8-μ m thickness Bi_0.85 Eu_0.15 FeO₃ and 0.2-μ m thickness of Bi_3.2 Y_0.8 Ti₃ O₁₂ thin film. The effects of annealing atmospheres (ambient atmosphere and oxygen) on the growth and properties of thin films were investigated. The results show that the intensities of the (117) diffraction peak of Bi_3.2Y_0.8Ti₃O ₁₂ film and (110) diffraction peak of Bi_0.85Eu_0.15FeO₃ annealed in oxygen is stronger than those annealed in an ambient atmosphere. The Bi_0.85Eu_0.15FeO₃/Bi_3.2Y_0.8Ti₃O₁₂ bilayer thin films annealed in the oxygen atmosphere exhibit the maximum remanent polarization (2mbi P_r) and remnant magnetization (2Mr) of 26 μ C/cm² and 3.44 emu/g, respectively. The improved magnetic and ferroelectric properties can be attributed to the elimination of defects, such as oxygen vacancy and vacancy complexes.