Magnetically tunable dielectric, impedance and magnetoelectric response in MnFe₂O₄/(Pb_1−xSr_x)TiO₃ composites thin films

We have synthesized piezomagnetic–piezoelectric composites thin films MnFe₂O₄/(Pb_1−xSr_x)TiO₃, where x=0.1, 0.2, and 0.3, using the metalorganic deposition (MOD) reaction method. The structural and microstructural analysis using the X-ray diffraction (XRD), AFM, and SEM reveals the presence of homogenous growth of both pervoskite and spinel phases in the composite films. Our results show that all the composites films exhibit good multiferroic as well as considerable magnetoelectric coupling. The impedance (Z′ and Z″) and electrical modulus (M′ and M″) Nyquist plots show distinct electrical responses with the magnetic field. Our analyses suggest that this electrical response arises due to the coexistence of the high resistive phase and the comparatively conductive phase in the MFO/PST composite films. The maximum magnetoelectric coefficient (α) is found to be 4.29 V Oe⁻¹ cm⁻¹ and 2.82 V Oe⁻¹ cm⁻¹ for compositions x=0.1 and 0.2. These values are substantially larger than those reported for bilayer composites thin films in literature and make them interesting for room temperature device applications. - Highlights: • Influence of Sr doping on multiferroic and magnetoelectric properties composites thin films of MnFe₂O₄ and (Pb, Sr)TiO₃. • Dielectric constant and dielectric loss with application of magnetic field. • Magnetically tunable AC electrical properties. • Magnetoelectric coupling in MnFe₂O₄/(Pb, Sr)TiO₃ composite films by passive method.