Ferroelectric and dielectric properties of [Pb(Ni1/3Nb2/3)O3-PbTiO3]/[(Ni0.2Cu0.2Zn0.6)Fe2O4] composites

A group of ferroelectric-ferromagnetic composites were developed from 0.8Pb(Ni1/3Nb2/3)O3-0.2PbTiO3 (PNNT) and (Ni0.2Cu0.2Zn0.6)Fe2O4 (NiCuZn) by a solid-state reaction. X-ray diffraction (XRD) and scanning electron microscope (SEM) studies showed that the composites were composed of PNNT phase and NiCuZn phase. The sintered composites exhibit typical ferroelectric hysteresis loops at room temperature. With an increase of PNNT content, the remnant polarization of composites decreases. Meanwhile, the remnant polarization and the coercive field show little asymmetric characterization. Frequency dependence of complex permittivity was also measured. With an increase in the PNNT content, the permittivity increases while the resonant frequency tends to decrease. Musal's effective medium theory was used to model the dielectric properties of composites. It was found that Musal's expression worked well over a wide range of composition.