Preparation and Dielectric Property of Ba(Fe0.5Nb0.5)O3 Based Composite Ceramic

The Ba(Fe0.5Nb0.5)O3 based composite ceramics with various glass content (10wt%-40wt%) were prepared by the powder sintering method. The microstructures and dielectric properties of the composite ceramics were investigated by the X-ray diffractometer, scanning electron microscope and impedance analyzer. The results show that the major phase of the composite ceramics was Ba(Fe0.5Nb0.5)O3 phase with cubic crystal structure. With the increase of the glass content, the grain sizes and porosities of the composite ceramics decreased gradually. The dielectric properties of the composite ceramics with different glass content were all excellent. The relative dielectric constant and tangent of dielectric loss angle both decreased with the increase of glass content. The breakdown strength of the composite ceramic with 40wt% glass reached the highest value of 296 kV·cm-1, while the energy storage density with 10wt% glass was the highest of 1.324 J·cm-3. The grain boundary phase plays an important role in improving the breakdown strength of Ba(Fe0.5Nb0.5)O3 based composite ceramics.