EFFECT OF SiO2 COATING ON MICROSTRUCTURE AND DIELECTRIC PROPERTIES OF BaZr0.1Fe0.02Ti0.88O3 CERAMICS

BaCO3, ZrO2, TiO2 and Fe2O3, were used as the starting materials, the BaZr0.1Fe0.02Ti0.88O3 powders are prepared using solid state synthesis method, the powders were coated with SiO2, the influence of different SiO2 package on the structure, micro morphology and dielectric properties of the samples is studied. The results show that all the samples have typical diffraction peaks of perovskite crystal; however, with the increase of the amount of inclusion of SiO2, a part of SiO2 enters into the crystal lattice, forming the BaTiSi4O11 phase in the body. The grain size of the sample coated with SiO2 is significantly larger than that of the sample not coated, with the continuous increase of the amount of coating, the grain size has no obvious change, and the size distribution is relatively uneven. With the increase of SiO2 content, the dielectric constant of the sample increases first and then decreases, and the dielectric loss of the sample decreases first and then increases. Due to the coating of SiO2, the dielectric constant is 2736, and the dielectric loss is 0.033 when the content of SiO2 is 1 wt%.