Facile synthesis of FeCo alloys with excellent microwave absorption in the whole Ku-band: Effect of Fe/Co atomic ratio

The different atomic ratios of FeCo alloys with various morphologies have been prepared through a simple liquid-thermal reduction method. It is found that the atomic ratio of ferrum and cobalt has great influence on the formation of FeCo alloys. Via adjusting Fe/Co atomic ratio (3:7, 5:5, 7:3), the surface of alloy becomes smooth gradually from distinct cone structure, and the saturation of alloys have been improved with the increase of Fe proportion. The impedance matching is also related tightly with atomic ratio and the best condition can be achieved by Fe7Co3 with lower dielectric constant and higher permeability. It is delighted to find that the optimal reflection loss (RL) value of Fe7Co3 can reach -53.6 dB at 143 GHz with a thin thickness of 1.55 mm and the RL values less than 10 dB can be gained from 11.2 to 18 GHz, which covering the whole Ku-band. The excellent performance derived from strong magnetic loss and well dielectric loss guarantees it as an ideal high-frequency microwave absorbent. (C) 2017 Elsevier B.V. All rights reserved.