Engineering Dielectric Loss of FeCo/Polyvinylpyrrolidone Core‐Shell Nanochains@Graphene Oxide Composites with Excellent Microwave Absorbing Properties

FeCo alloy nanoparticles, as a kind of material with high saturation magnetization, have attracted wide attention in electromagnetic (EM) wave research. However, its application as a wave‐absorbing material is limited by its poor magnetic anisotropy and antioxidant properties. Herein, novel FeCo/Polyvinylpyrrolidone core‐shell nanochains@graphene oxide (GO) composites are successfully fabricated with superior microwave‐absorbing properties. The composites perform excellently in absorbing EM wave, with a strong reflection loss (RL) of −40.94 dB at 14.25 GHz, covering from 10.95 to 15.85 GHz (RL