Effect of doping SiO2 on high-frequency magnetic properties for W-type barium ferrite

Abstract

The microstructure, static and dynamic magnetic and dielectric properties of BaCo1.3Zn0.7Fe16O27 doped with small amounts of SiO2 have been investigated. The results show that the crystal structure and static magnetic properties have no obvious changes as SiO2 varies from 0 to 1 wt %. However, the complex permittivity and complex permeability could be significantly modified by SiO2 doping. Due to the doping, both real and imaginary permittivity are greatly increased. The increase has its origin in the formation of Fe2+, due to minor Si4+ ions entering the crystal lattice of barium ferrites. The complex permeability spectra can be decomposed into two components, which are associated with natural resonance and wall resonance. By doping with SiO2, the contribution of wall resonance to the static permeability increases, while the contribution of the natural resonance decreases. The overall static permeability is increased as a result.