PHASE STRUCTURE AND DIELECTRIC PROPERTIES OF FERROELECTRICS AND FERRITE MIXED COMPOSITES

The composite material was prepared by mixing Pb (Ni_1/3Nb_2/3) O₃-PbTiO₃-based ferroelectrics and NiCuZn ferrite material. The phase structure and dielectric properties of the composite were investigated. The dielectric constant of composite material simulated by amending the logarithm equation and the amending coefficient were estimated. The results show that there are no other phases in the composite except dielectric phases and ferrite phase, indicating the two materials chosen in the present study are chemically compatible. It is found that there is no conventional dielectric peak appearing in the plot of dielectric constant versus temperature. The ferroelectric phase plays a main role in the dielectric constant at low temperature range from -80℃ to 20℃. The dielectric constant and the dissipation factor of composite material continuously increase with increasing temperature, which should be attributed to the leakance induced by the ferrite phase. The dielectric constant of composite material simulated was in agreement with experimental results.