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. Ni 0.5 Zn 0.5 Fe 2 O 4 /Ba 0.8 Sr 0.2 TiO 3 composites have been prepared by the conventional high-temperature solid-state method and the effects of Al 2 O 3 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 Al 2 O 3 can enhance the density and promote uniform growth of particle size. The sample with 1 wt.% Al 2 O 3 addition exhibited the largest dielectric constant and lowest dielectric loss (< 0.05 at 1 kHz) at high temperature (> 354°C). The sample with 3 wt.% Al 2 O 3 addition presented the best ferroelectric properties, with the highest values of residual polarization ( P r = 2.2150 μ C/cm 2 ) and coercive field ( E c = 30.6527 kV/cm) among the specimens. The remanent magnetization ( M r ) and saturated magnetization ( M s ) decreased with increasing Al 2 O 3 content. In short, addition of Al 2 O 3 caused changes in the grain size, density, and defects, and addition of a certain amount of Al 2 O 3 can improve the magnetoelectric properties.