Studies on electrical properties and the magnetoelectric effect on ferroelectric-rich(x)Ni0.8Zn0.2Fe2O4+(1−x) PZT ME composites

Abstract

Magnetoelectric composites with ferrite–ferroelectric composition(x)Ni0.8Zn0.2Fe2O4+(1−x) PZT (lead zirconatetitanate (PbZr0.52Ti0.48O3) used as aferroelectric phase) in which x varies as 0, 0.15, 0.30, 0.45 and 1 mol% were prepared by using a conventional ceramicdouble-sintering method. Phase analysis was carried out using the x-ray diffractiontechnique, which confirms a cubic spinel structure for the ferrite and tetragonalperovskite structure for the ferroelectric phase. The variation of the dielectric constant(ε′) and losstangent (tanδ) in the frequency range 20 Hz–1 MHz were studied. The conduction phenomenon is explainedon the basis of a small polaron hopping model. The confirmation of this phenomenonwas made with the help of ac conductivity measurements. The dc resistivity wasmeasured as a function of temperature in the range from room temperature to800 °C. Hysteresis measurements were performed to determine the saturation magnetization(Ms) and magneticmoment (ηB). The static magnetoelectric conversion factor(dE/dH)H was measured as a function of the magnetic field. All composites show a linear decrease ofmagnetoelectric conversion in the presence of a static magnetic field.