Effect of Al2O3 Addition on Magnetoelectric Properties of Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 Composite Ceramics

Magnetoelectric composites have attracted widespread attention during the past few decades due to their strong magnetoelectric coupling effect and potential applications above room temperature. Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 composites have been prepared by the conventional high-temperature solid-state method and the effects of Al2O3 addition on their microstructure, dielectric, ferroelectric, and magnetic properties studied. x-Ray diffraction (XRD) analysis confirmed the biphase structure of the composites. scanning electron microscopy (SEM) showed that addition of a certain amount of Al2O3 can enhance the density and promote uniform growth of particle size. The sample with 1 wt.% Al2O3 addition exhibited the largest dielectric constant and lowest dielectric loss ( 354°C). The sample with 3 wt.% Al2O3 addition presented the best ferroelectric properties, with the highest values of residual polarization (Pr = 2.2150 μC/cm2) and coercive field (Ec = 30.6527 kV/cm) among the specimens. The remanent magnetization (Mr) and saturated magnetization (Ms) decreased with increasing Al2O3 content. In short, addition of Al2O3 caused changes in the grain size, density, and defects, and addition of a certain amount of Al2O3 can improve the magnetoelectric properties.