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

Abstract

Amorphous FeCo nanowires (NWs) with the average diameter of 120[Formula: see text]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[Formula: see text]mm coating thickness, the reflection loss (RL) peaks of Fe3Co7, Fe5Co5 and Fe7Co3 NWs are [Formula: see text]25.88[Formula: see text]dB at 4[Formula: see text]GHz, [Formula: see text]19.06[Formula: see text]dB at 4.24[Formula: see text]GHz and [Formula: see text]21.98[Formula: see text]dB at 5.44[Formula: see text]GHz. The related efficient absorption bandwidths ([Formula: see text]10 dB) of Fe3Co7 NWs, Fe5Co5 NWs and Fe7Co3 NWs are 5.40[Formula: see text]GHz, 3.52[Formula: see text]GHz and 4.91[Formula: see text]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.