Achievement of superior microwave absorption performance and ultra-wide regulation frequency range in Fe-Co-Nd via tuning the phase constitution and crystallinity

Abstract

To achieve superior microwave absorption and ultra-wide regulation frequency range under a restricted thickness, (FeCo)100−xNdx (0 ≤ x ≤ 15) powders were prepared through a single roller melt spinning technique. The introduction of Nd decreases the crystallinity of FeCo phase and promotes the formation of secondary Nd2(FeCo)17 phase, which results in apparent reduction of electromagnetic (EM) parameters. The correlations between EM parameters and final microwave absorption properties are discussed in detail. It is found that the suppressed EM parameters modifies the coordination between impedance matching and attenuation performance, ultimately leading to superior microwave absorption performance with broad bandwidth of 6.92 + GHz and RLmin of −52.5 dB under thickness of only 1.45 mm. Moreover, due to the dramatic decline of |μr|·|εr| values, the qualified RL of the samples covers almost all the test frequency (2–18 GHz) with thin thickness of 2 mm, showing great practical value in full-spectrum microwave absorption area with a restricted coating thickness.