Synergistic spin–lattice coupling and multifunctional property tuning in Sm–Mn co-doped BiFeO 3 ceramics

This study investigates the impact of Sm and Mn co-doping on the structural, electronic, and magnetic properties of BiFeO 3 ceramics (BFO, BSFO91, BSFMO91) synthesized via solid-state reaction. X-ray diffraction confirmed that co-doping suppressed the nonpolar Pbam phase and stabilized the rhombohedral R3c structure in BSFMO91. Distortion of FeO 6 octahedra reduced the bandgap (1.58 eV) and Urbach energy (0.502 eV), indicating improved lattice order. Ferroelectric measurements showed enhanced remanent polarization (0.154 μC/cm 2 ) and measurable recoverable energy storage. Electron spin resonance revealed strong spin–orbit interaction (g = 2.260), while magnetic studies indicated increased moment (0.025 μB/f.u.) and canting (0.289°). Temperature-dependent analysis confirmed weak ferromagnetism below 10 K. The findings highlight BSFMO91 as a promising multifunctional material for further exploration in magnetoelectric systems.