Low Loss Magneto-Dielectric Composite Ceramics Ba3Co2Fe24O41/SrTiO3 for High-Frequency Applications

Magneto-dielectric composite ceramics Ba3Co2Fe24O41/SrTiO3 (Co(2)Z/STO) loading with high volume fraction of hexaferrite Co(2)Z (fCo2Z=60%-95%) are successfully prepared by a hybrid process. The microstructures with homogeneously dispersed constituent grains are observed in these composites. The composites loading with 60%-80% hexaferrite possess stable magneto-dielectric properties in the frequency range from 10MHz to 1GHz with both low dielectric loss and magnetic loss. For the composite loading with 60% Co(2)Z, the relative permittivity is 28.08 and permeability is 4.46 (at 10MHz), the dielectric loss tangent keeps below 0.009 within the frequency range from 10MHz to 1GHz. Also, it possesses a magnetic loss tangent of 0.006 and 0.144 at 50MHz and 1GHz, respectively, which are much lower than 0.056 and 1.242 of the single Co(2)Z phase at the same frequency. These excellent properties indicate that the low-loss Co(2)Z/STO composite ceramic is a new kind of multifunctional magneto-dielectric material with potential for high-frequency electromagnetic device applications.