Nowadays, constructing electromagnetic wave (EMW) absorbing materials with high

absorption strength and wide response frequency is an urgent demand and also a

challenge. In this work, the bimetallic organic precursors of cobalt/iron nitrilotriacetic

acid chelate nanowires (Co/Fe-NTAC) were prepared by one-step hydrothermal self

polymerization strategy. Then, the CoxFey@C nanocomposite fibers with different

Co/Fe atomic ratios were synthesized by directly calcining the Co/Fe-NTAC

precursors. Notably, when the atomic ratio of Co/Fe is 1:1, the sample exhibits high

efficient microwave absorption performance with the minimum reflection loss (RL) of -

117.8 dB, whose effective absorption bandwidth (EAB, RL ≤ -10 dB) reaches up to

12.6 GHz (5.4-18 GHz) at the same thickness. The outstanding EMW attenuation

properties are attributed to the strong magnetic loss, multiple heterogeneous interface

polarizations, synergistic effects between magnetic cores and dielectric shells, as well

as optimal impedance matching. Especially, the heterointerfaces polarization behavior

and ferromagnetic coupling effect were verified by High-Frequency Structure Simulator

(HFSS). The Radar Cross-Sectional (RCS) values of the optimized sample are all

lower than -10 dBm2 in the range of -60?< θ < 60?, which can achieve almost full

angle coverage in the practical environment. This work provides inspiration and

strategy for the facile construction of high-intensity and ultra-wideband EMW

absorbers.