Nickel Zinc Ferrite As The Base Of The Performance Of Magnetoelectric Composite Materials Research

Ferromagnetic materials and magnetoelectric materials have been widely studied by more and more experiments. And they have been diffusely used in many electronic devices in modern technology. In this work, we studied the influence of nickel-zinc ratio on microstructure, magnetic and dielectric properties of Ni-Zn ferrites. Then we chose a proper component to composite with the ferroelectric material and studied the magnetic and dielectric properties. We studied the microstructure, magnetic and dielectric properties of NiFe2O4-BaTiO3material synthesized by hydrothermal method.We prepared the Ni(1-x)ZnxFe2O4(x=0-1) ferrite by conventional solid-state method and got the pure spinel structure phase in the temperature range of1150℃to1250℃. The grain size of samples increased with increasing zinc contents and sintering temperature. It presented a Debye relaxation in the dielectric measurement. The magnetic Curie temperature decreased lineally with zinc content. The permeability and saturation magnetization increased firstly with increasing zinc content and then reduced. The coercivity of samples sintered at1200℃increased with the increase of zinc content and then decreased, which was similar to the saturation magnetization. However, samples sintered at1250℃decreased with zinc concentration monotonously.Ni0.37Zn0.63Fe2O4ferrite was chosen to compose with Pb(Zr0.52Ti0.4s)O3for the magnetoelectric material:xNi0.37Zn0.63Fe2O4-(1-x)Pb(Zr0.52Ti0.48)O3. The composites were prepared without the third phase. With increasing the ferrites concentration, the density and dielectric constant decreased and the permeability, tangent loss, magnetic Curie temperature and ferroelectric temperature increased.We prepared the NiFe2O4-BaTiO3composites by a hydrothermal method with putting all the raw materials together. X-ray diffraction and SEM technology were used to analyze the structure and microstructure. We also studied the dielectric constant and permeability changing with frequency and temperature. It made clear that the structure of BaTiO3in the composite changed from tetragonal structure to hexagonal structure. There come up hexagon shaped BTO particles and near-spherical shaped particles. With increasing the content of ferrites, the dielectric constant and permeability increased, and the dielectric Curie temperature got lower while the magnetic Curie temperature got higher, close to that of NiFe2O4.