Magnetoelectric and magnetodielectric coupling in partially Ni-doped CoFe2O4 and 0.15(Ba0.7Ca0.3TiO3)-0.85(BaZr0.2Ti0.8O3) composites prepared via clean microwave sintering

Abstract

Multiferroic composites with high magnetoelectric coupling at room temperature are considered as the most significant materials due to their potential application in many electronic devices. Furthermore, ultrafast, eco-friendly energy-efficient innovative techniques to develop multifunctional materials have attracted abundant importance. In this study, we report on ferrite–ferroelectric particulate composites prepared via clean, eco-friendly, ultrafast, hybrid-microwave sintering. Partially Ni-doped CoFe2O4 was selected as a magnetostrictive phase due to its considerable value of the magnetostriction coefficient, λ11 ≈ −118 ppm, saturation magnetization Ms ≈ 80 emu/gm, and μB ≈ 3.37 and mixed with a 0.15(Ba0·7Ca0·3TiO3)–0.85(BaZr0·2Ti0·8O3) ferroelectric phase in different content ratios of 10%, 20%, 30%, and 40%. The multiferroic properties of the sintered composite samples were investigated considering magnetoelectric and magnetodielectric couplings. The highest value of the magnetoelectric coupling coefficient, αME = 22..09 mV/Oe·cm was observed for the composite with 40% ferrite content, while similar composite exhibits the higher value of the magnetodielectric coupling coefficient which is 3.52% at 1 kHz (frequency) and 1 T (magnetic field). X-ray diffraction and Raman spectroscopy confirmed the phases of the ferrite and ferroelectric constituents without revealing any additional phases. The impedance and AC conductivity of the multiferroic compositions were analyzed under various temperatures and by applying a magnetic field at room temperature. The temperature-dependent dielectric nature confirms that the addition of Ni-doped CoFe2O4 into a ferroelectric constituent substantially influences the dielectric constant in the paraelectric region. These results may offer an alternative technique for the preparation of multiferroic composites with improved coupling properties. © 2020 Elsevier B.V.