AC measurements, impedance spectroscopy analysis, and magnetic properties of Ni_0.5Zn_0.5Fe₂O₄/BaTiO₃ multiferroic composites

Multiferroics composite materials have been widely used in several applications, such as ceramic supercapacitors and multifunctional and active devices, owing to their high permittivity with ferroelectric and magnetic performance even at room temperature. The chosen preparation technique can be one of the most effective ways for obtaining multiferroic composite with different properties for the same composite. Here, multiferroic composite materials, (x) wt.% Ni_0.5Zn_0.5Fe₂O₄ (NZF)-(100-x) wt.% BaTiO₃ (BT) (x = 25, 50, 75) were prepared by the co-precipitation synthesis route. The prepared multiferroic samples were characterized with various techniques like X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDXS), and vibrating sample magnetometer (VSM). The magnetic and AC electrical properties like conductivity, dielectric constant, dissipation factor (dielectric loss), and impedance spectroscopy analysis were studied in detail with different frequencies and temperatures. In our case, preparing nanosized NZF on or between microscale BT could enhance the electrical properties by decreasing the porosity (P) percentage, which reaches a low value for the sample x = 50 wt%, and increasing the conductivity. A relatively high dielectric constant (ε‘) at low frequencies and high temperatures was obtained, which is one of the main contributions in modern applications like a ceramic supercapacitor. Also, the studied samples show low dielectric loss (tanδ) values suggesting that it could be a contender for use in high-frequency microwave devices and tunable frequency filters.