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

Magnetoelectric composites with ferrite-ferroelectric composition (x) Ni0.8Zn0.2Fe2O4 + (1-x) PZT (lead zirconate titanate (PbZr0.52Ti0.48O3) used as a ferroelectric phase) in which x varies as 0, 0.15, 0.30, 0.45 and 1 mol% were prepared by using a conventional ceramic double-sintering method. Phase analysis was carried out using the x-ray diffraction technique, which confirms a cubic spinel structure for the ferrite and tetragonal perovskite structure for the ferroelectric phase. The variation of the dielectric constant (e') and loss tangent (tan delta) in the frequency range 20 Hz-1 MHz were studied. The conduction phenomenon is explained on the basis of a small polaron hopping model. The confirmation of this phenomenon was made with the help of ac conductivity measurements. The dc resistivity was measured as a function of temperature in the range from room temperature to 800 degrees C. Hysteresis measurements were performed to determine the saturation magnetization (M-s) and magnetic moment (eta B). The static magnetoelectric conversion factor (dE/dH) (H) was measured as a function of the magnetic field. All composites show a linear decrease of magnetoelectric conversion in the presence of a static magnetic field.