Structural Control and Magnetoelectric Synergistic Enhancement Effect of BiFeO ₃ –SrTiO ₃ Composite Structure

BiFeO 3 (BFO) and SrTiO 3 (STO) composite structure (BFO–STO) was prepared using the solid-state reaction method, and the effects of STO introduction on the structure, magnetic properties and ferroelectric properties of BFO were systematically investigated. XRD and TEM analyses indicated that STO was successfully incorporated into the BFO lattice to form a uniform composite structure, and increased the tilt angle of the FeO 6 octahedra. Ferromagnetic testing showed that the introduction of STO significantly enhanced the ferromagnetic properties of BFO, reaching an optimal value at [Formula: see text], while the ferroelectric hysteresis loop indicated that this composition also exhibited the highest residual polarization strength (0.35[Formula: see text][Formula: see text]C/cm[Formula: see text]. DFT calculations reveal that STO introduction promotes charge transfer from Ti to Fe, enhancing Fe-O-Ti super-exchange interactions, thereby synergistically optimizing the system’s magnetoelectric properties. This study provides new insights into regulating the magnetoelectric coupling effects in BFO-based materials.