Ba-Doped BiFeO₃ Nanomaterials Synthesized via Sol-Gel Auto-Combustion: Structural, Dielectric, Ferroelectric, and Magnetic Properties

Abstract

BiFeO₃ is a unique room-temperature multiferroic material exhibiting both ferroelectric and antiferromagnetic ordering, but its applications are limited by weak magnetic properties and high leakage currents. In this study, Ba-doped BiFeO₃ nanomaterials with compositions BaxBi₁₋ₓFeO₃ (x = 0.0, 0.10, 0.20, 0.25, 0.30) were synthesized via the sol-gel auto-combustion method to enhance multiferroic performance. X-ray diffraction confirmed a rhombohedral perovskite structure with minor secondary phases, while Ba doping induced lattice distortion, reduced crystallite size, and increased strain. Dielectric measurements showed a progressive increase in dielectric constant and reduced dielectric loss with higher Ba content, attributed to improved polarization and suppressed leakage. Ferroelectric (P–E) loops exhibited enhanced remanent polarization and improved loop squareness, indicating better domain alignment and lower conductivity. Magnetic (M–H) hysteresis loops revealed significant enhancement in remanent and saturation magnetization with increasing Ba concentration, due to spin cycloid suppression and the presence of uncompensated surface spins. These results demonstrate that Ba substitution is an effective route to tailor the structure and enhance the multifunctional properties of BiFeO₃ nanomaterials. The improved multiferroic behavior makes them strong candidates for applications in spintronic devices, magnetoelectric sensors, and multifunctional nanoelectronics.