Amorphous Bimetallic Nanowires with High-Performance Microwave Absorption: A Case for FeCo Nanowires

Amorphous FeCo nanowires (NWs) with the average diameter of 120 nm were successfully prepared with a magnetic-field-assisted (MFA) hydrothermal method. Rapid reaction time was adopted to obtain amorphous FeCo NWs, being checked by XRD and TEM. Tuning the stoichiometric ratio of Fe/Co content meets the optimal impedance matching under different absorption frequency, making both improved intensities and frequency ranges of microwave absorption. For example, under 3 mm coating thickness, the reflection loss (RL) peaks of Fe 3 Co 7 , Fe 5 Co 5 and Fe 7 Co 3 NWs are − 25.88 dB at 4 GHz, − 19.06 dB at 4.24 GHz and − 21.98 dB at 5.44 GHz. The related efficient absorption bandwidths ( f E < − 10 dB) of Fe 3 Co 7 NWs, Fe 5 Co 5 NWs and Fe 7 Co 3 NWs are 5.40 GHz, 3.52 GHz and 4.91 GHz, respectively. It is ascribed to integrating enhanced dielectric/conductive losses, negligible damages from eddy current effect and good impedance matching for high-performance FeCo NWs absorbers. This work paves a new path on synthesizing bimetallic wire-like nanostructures for microwave absorption demands.