Study on electromagnetic properties of MgCuZn ferrite/BaTiO3 composites

The low temperature co-firing compatibility between ferrite and dielectric materials is the key issue in the production of multilayer chip inductive-capacitive filters. A new composite comprising dielectric-ferrite ceramics was prepared by mixing MgCuZn ferrite with BaTiO3 based commercial dielectrics. (Mg0.25Cu0.20Zn0.55)Fe2O4 ferrite powder was synthesized through so-gel auto-combustion method. Commercial Z5U type dielectric powder was used as such. Dielectric-ferrite mixed powder was uniaxially pressed into toroids and pellets. Specimens were sintered at 950 degrees C. The co-sintering behavior of dielectric-ferrite in composite was investigated using thermo-mechanical analyzer. The co-existence of spinel ferrite and BaTiO3 pure phases were confirmed by X-ray diffraction analysis. The permittivity of composite continuously decreases and permeability increases with increasing ferrite content. Dielectric and magnetic losses in the composite increased due to the generation of interfacial charges in the ferrite-ferroelectric interface. (C) 2011 Elsevier B.V. All rights reserved.