Compositional tuning of phase interaction and strong magnetoelectric response in SRM-LNFO ceramic composites

A novel series of magnetoelectric composites (1 - x)SrFe₁₂O₁₉-xLa_0.5Nd_0.5FeO₃ (x = 0.00-1.00) was synthesized via a citrate-assisted sol-gel method to explore the interplay between structural evolution and multifunctional properties. X-ray diffraction and Raman spectroscopy revealed phase coexistence with crystallite sizes increasing from 28 nm to 42 nm with rising perovskite content. Microstructural analysis showed particle sizes ranging from 0.19 µm to 0.54 µm, driven by compositional tuning of hexaferrite and perovskite phases. Mössbauer and XPS studies confirmed Fe³⁺ valence states and interfacial electronic interactions influencing magnetoelectric coupling. Magnetic characterization demonstrated a saturation magnetization decrease from 52.75 emu g^-1 to 9.22 emu g^-1 and a coercivity peak at 8.59 kOe for intermediate compositions due to exchange coupling effects. Ferroelectric measurements showed a remanent polarization of 1.21 µC cm^-2 at x = 0.25 with corresponding leakage currents as low as 0.03 mA cm^-2 for higher perovskite content. The optimized composition (x = 0.50) exhibited the highest magnetoelectric voltage output of 15.06 mV and coupling coefficient peak, highlighting efficient strain-mediated interphase interactions. These findings position SrFe₁₂O₁₉-La_0.5Nd_0.5FeO₃ composites as promising candidates for magnetic sensors, multifunctional devices, and EMI shielding, providing valuable insights into structure-property relationships in oxide magnetoelectric composites.