Research on dielectric and ferroelectric properties of ferroelectric/ferrite composites

A group of ferroelectric and ferrite composites with composition (1-x)NiFe₂O₄ + xPbZr_0.52Ti_0.48O₃ (where x=0.5, 0.6, 0.7, 0.8) was prepared by the standard ceramic reaction method. XRD and SEM revealed a ferroelectric phase and ferrite phase without any other phase. The investigation of resistivity and piezoelectric coefficient showed the best sintering temperature was 1220°C. The dependence of dielectric constant with temperature had been studied. The Curie temperature was about 390°C without any change at all studied frequencies. The phase transition of composite was the ferroelectric to the paraelectric phase transition. The hysteresis loop appeared a phenomenon of double hysteresis loop. The remnant polarization of the composites was lower. With the increase content of the ferroelectric phase, the remnant polarization increased, and the ferroelectric properties also enhanced.