Interplay of Magnetic Ordering and Dielectric Response in 0.9Bi2Fe4O9/0.1CoFe2O4 Composite

Abstract

The sol–gel auto-combustion method was used to synthesize the composite 0.9Bi2Fe4O9/0.1CoFe2O4, and its structural, magnetic, and dielectric properties were systematically studied in the present work. Rietveld refinement of room-temperature (RT) X-ray diffraction (XRD) patterns confirmed the composite's biphasic nature. The zero-field cooled-field-cooled magnetization data show the strong magnetic irreversibility nature of the composite below 200 K, and the openings of an M–H hysteresis loop at temperatures 10 K and 150 K confirm the onset of weak ferromagnetism with magnetic glass–like characteristics in the composite 0.9BFO/0.1CFO [1]. An anomaly is observed near the magnetic transition temperature in ε', and the contrasting nature of tanδ below and above the transition temperature was observed over the same temperature range. These features suggest a possible coupling between the magnetic and electric order parameters [2]. The presence of magnetodielectric (MD) coupling enhances the composite's potential for multifunctional applications, such as memory devices, sensors, and actuators [3] [4].