Effective dielectric and magnetic properties of (Ni-Co-Cu)ferrite/BTO composites

Particulate composites of Ni0.93Co0.02Cu0.05Fe2O4 as a ferrite phase and BaTiO3 as a ferroelectric phase were synthesized by normal ceramic method with variations of mole percentage. The structural analysis of both the constituent phases and their composites carried out by X-ray diffraction (XRD) pattern showed the cubic spinel structure for ferrite phase and tetragonal perovskite structure for ferroelectric phase. The phase percentage after final sintering is well consistent with the mole percentage of constituent phase used for synthesis. The surface morphological studies were carried out to calculate average grain size. The effect of temperature on dielectric properties of composites and their constituent phases is discussed. With increasing content of BaTiO3 in composites, the dielectric constant decreased and the Curie temperature shift towards the low temperature side. The high value of dielectric constant indicates the applicability of these composites as a capacitor material. The hysteresis measurements were carried out under the influence of dc magnetic field to determine the saturation magnetization, remanent magnetization and magnetic moment for all the composites. The variation in magnetic behavior with the composition of constituent phases was measured as a function of the applied dc magnetic field. (C) 2008 Elsevier B.V. All rights reserved.