Preparation and Investigations of the Magnetoelectric Properties of (Ni_0.5Zn_0.5Fe₂O₄) _x [(Na_0.5Bi_0.5)_0.7Ba_0.3TiO₃]_1-x (x=0.3, 0.5) Nanocomposite Ceramics for Magnetic Field Sensor Applications

A multiferroic nanocomposite was derived by considering Ni0.5Zn0.5Fe2O4 (NZFO) and Ba-doped Na0.5Bi0.5TiO3 (NBBTO) as the constituent components. Nanoparticles of (Na0.5Bi0.5)(0.7)Ba0.3TiO3 synthesized by the sol-gel technique were successfully incorporated into NZFO during its preparation. For this experiment, two distinct stoichiometric ratios were taken: (NZFO)(0.3)(NBBTO)(0.7) (NZFO-NBBTO-1) and (NZFO)(0.5)(NBBTO)(0.5) (NZFO-NBBTO-2). The X-ray diffractograms were subjected to Rietveld refinement, confirming the desired phase formation without any impurity. Images captured by field-emission scanning electron microscopy showed that particles are uniformly scattered with distinct spherical morphology. The lack of impurity elements was verified by energy-dispersive X-ray spectroscopy (EDAX), and EDAX mapping showed that the constituent elements were distributed uniformly. The magnetic moment variation from 300 to 50 K was analyzed to identify magnetic phases in the composites. The presence of nearly saturated loops was revealed in both composites by the zero-field-cooled and field-cooled magnetization data as a function of the temperature and magnetization versus field loops, as recorded by vibrating sample magnetometry (VSM). The maximum magnetization was observed to be 16.76 emu/g for NZFO-NBBTO-1 and 22.45 emu/g for NZFO-NBBTO-2 at 300 K. At 300 K, both composites exhibited good dielectric properties, with a dielectric strength of similar to 320 and a low loss of similar to 0.5. Direct observation of the ferroelectric loop indicated that NZFO-NBBTO-1 exhibited better ferroelectricity (P-max similar to 0.018 mu c/cm(2)) compared to NZFO-NBBTO-2 (P-max similar to 0.01 mu c/cm(2)). The magnetocapacitance coefficient was also higher in NZFO-NBBTO-1 (similar to 4%) than in NZFO-NBBTO-2 (similar to 3%). In general, the findings indicate that NZFO-NBBTO-1 shows great promise as a potential candidate for a magnetoelectric multiferroic material that could be used for the development of magnetic field sensors, spintronic devices, sensors, microelectronic devices, actuators, and electronic memory devices.