A Comprehensive study on the structural, Magnetic, and Dielectric Characteristics of Bi2Fe4O9/NiFe2O4 Composite

Abstract

The composite 0.9Bi2Fe4O9/0.1Ni2Fe4O9 was synthesized via the sol–gel auto-combustion method, and its structural, magnetic, and dielectric properties were systematically investigated in the present work. Rietveld refinement of room-temperature (RT) X-ray diffraction (XRD) patterns confirmed the coexistence of dual-phase formation. The microstructural analysis indicated non-uniform grain dispersion, with the average grain size estimated to be around ~ 0.5μm. The RT M–H curve of the composite exhibited low saturation magnetization of ~5 emu/g under an applied field of ±15 kOe. Temperature-dependent magnetization shows the Curie transition of the composite around ~ 830 K. Dielectric measurements as a function of temperature at constant frequencies showed an anomaly near 300 K, indicating magnetodielectric (MD) coupling. The presence of MD coupling enhances the potential of the composite for multifunctional applications such as memory devices, sensors, and actuators.