Magnetic sputtering of FeNi/C bilayer film on SiC fibers for effective microwave absorption in the low-frequency region

Abstract It is a great challenge in promoting a microwave absorber with excellent absorbing properties in the low-frequency region. Herein, SiC fibers (SiCf) coated by a bilayer of FeNi/C (SiCf/FeNi/C) are fabricated via a two-step magnetron sputtering method. Owing to the improved dielectric loss, magnetic loss, and impedance matching, the reflection loss of SiCf/FeNi/C is remarkably enhanced. Accordingly, the minimum reflection loss of SiCf/FeNi/C reaches -26.18 dB at a low-frequency region of 3.44 GHz. Besides, the mechanic strength of SiCf/FeNi/C maintains at 2.32 GPa as compared to as-received SiCf. Thus, SiCf/FeNi/C is expected to be an ideal structure material to meet low-frequency microwave absorption requests.