Development of zinc ferrite and activated charcoal based composites for microwave absorption analysis in X-band

Microwave absorbing composites comprising of Zinc Ferrite and Activated Charcoal (AC) are synthesized by mechanical alloying method. The low-density zinc spinel ferrite is synthesized by auto combustion method. Activated charcoal is produced by using high energy planetary ball mill. The composites comprising of activated charcoal and zinc ferrite are developed by using ball milling method. The as-synthesized zinc ferrite is observed to have a saturation magnetization of 35.15 emu/g. The addition of AC in the ferrite matrix results in gradual decrease in the saturation magnetization. The influences of activated charcoal on the magnetic and dielectric properties of zinc ferrite are also explored for microwave absorption applications in X-band. The composite medium containing 25% zinc ferrite and 75% activated charcoal showed excellent microwave absorbing behavior in X-band. It achieves a minimum reflection loss of −14.46 dB at 9.27 GHz with effective coating thickness of 2.3 mm.