Enhanced microwave absorbing properties and heat resistance of carbonyl iron by electroless plating Co

•The Co-coated carbonyl iron Co(CI) particles were prepared by electroless plating.•The electromagnetic wave absorbing properties of Co(CI) particles were studied.•The heat treatment on the absorbing property of Co(CI) particles was studied.•The Co(CI) particles have good absorbing property when compared with CI.

Co coated carbonyl iron particles (Co (CI)) are fabricated through electroless plating method, and the electromagnetic microwave absorbing properties are investigated in the frequencies during 8.2–12.4 GHz. The complex permittivity of CI particles after electroless plating Co is higher than that of raw CI particles due to improvment of the polarization process. Furthermore, according to the XRD and TG results, the Co layer can enhance the heat resistance of CI particles. The bandwidth below −10 dB can reach 3.9 GHz for the Co(CI) absorbent. The results indicate that the electroless plating Co not only enhances the absorbing properties but also improves the heat resistance of CI.