A comparative study of microstructure, magnetic, and electromagnetic properties of Zn₂W hexaferrite prepared by sol–gel and solid-state reaction methods

In this work, Zn₂W hexaferrite was prepared by sol–gel (SG) and solid-state reaction (SSR) methods. The dependency of the microstructure, magnetic, and electromagnetic properties of the obtained Zn₂W hexaferrite on the two different preparation methods and the sintering temperature was investigated. First, single-phase Zn₂W hexaferrite was obtained by the SG method at sintering temperatures higher than 1250 °C, but this was not the case with the SSR method. Second, the Zn₂W hexaferrite prepared by the SG method had a larger grain size than those prepared by the SSR method under the same sintering conditions due to the higher activity of the obtained nanosized precursor powder. Third, the saturation magnetization obtained the highest value herein of 77.48 emu/g from the Zn₂W hexaferrite prepared by the SG method sintered at 1250 °C, which is higher than the value of 72.49 emu/g from the Zn₂W hexaferrite prepared by the SSR method sintered at 1300 °C. Finally, the values of reflection losses reached a maximum of 22.4 dB at 17.0 GHz with the bandwidth of 0.87 GHz over 10 and 29.5 dB at 17.9 GHz with around the bandwidth of 1.38 GHz for the hexaferrite prepared by the SG method and SSR methods, respectively, which meets the absorption requirement for high-frequency microwave applications.