Effect of pH value on electromagnetic loss properties of Co–Zn ferrite prepared via coprecipitation method

• Co–Zn ferrite was prepared by coprecipitation method with different pH values.
• To obtain pure Co–Zn ferrite, the theoretical pH values were 9–11.
• Microstructure and electromagnetic properties can be tuned by varying pH values.
• Co–Zn ferrite prepared with pH=9 performed well electromagnetic loss properties.

In this paper, the cobalt zinc ferrite was prepared by coprecipitation method at different pH conditions. The influence of pH values on the coprecipitation reaction was theoretically analyzed at first. The calculated results showed that the pH values should be controlled in the range of 9–11 to form the stable precipitation. The XRD investigation was used to further confirm the formation of the composite on specific pH values. In addition, the morphological study revealed that the average particle size of the composite decreased from 40 nm to 30 nm when the pH value increased from 9–11. The variation of microstructure plays a critical role in controlling the electromagnetic properties. From the electromagnetic analysis, the dielectric loss factor was 0.02–0.07 and magnetic loss factor was 0.2–0.5 for the composite synthesized at pH of 9, which presents dramatically improved dielectric loss and magnetic loss properties than the samples prepared at pH of 10 and 11. The as-prepared cobalt zinc ferrite are highly promising to be used as microwave absorption materials.