The preparation and microwave properties of Ba2ZnzCo2−zFe12O22 hexaferrites

Ba2ZnZCo2–ZFe12O22 hexaferrites with Z=0.0, 0.4, 1.2, 1.6 and 2.0 were prepared at temperature 1100 °C for 5 h by citrate sol-gel process. The complex dielectric constant and complex permeability of hexaferrite–paraffin wax composites had been measured by the transmission/reflection coaxial line method in the range from 100 MHz to 6 GHz. The results show that both the complex dielectric constant and dielectric loss decrease as measuring frequency increases, the dielectric loss were near to zero at high frequency. It also shows that the real part of permeability decreases as the frequency increases in the whole range of measuring frequency. The natural phenomenon is observed in μ″ spectrum for Zn0.4Co1.6Y, Zn1.2Co0.8Y, Zn1.6Co0.4Y and Zn2Y hexaferrites. The substitution of Zinc ions had a close effect on the microwave properties of Ba2ZnZCo2–ZFe12O22 ferrites, the higher the Zinc ions content, the lower the natural resonance frequency is.