GO-decorated chain-like Fe2O3/FeMn2O4 NPs (GO-Fe2O3/FeMn2O4 nanocomposites) with ultrabroad band microwave absorption

In this study, GO-Fe2O3/FeMn2O4 nanocomposites were synthesized in which the chain-like Fe2O3/FeMn2O4 NPs were decorated on GO sheets. The crystalline phases of Fe2O3 and FeMn2O4 were recognized from the XRD pattern. TEM images showed that the oval-shaped Fe2O3/FeMn2O4 NPs with an almost narrow size distribution (60-80 nm) were connected to form chains. The Fe2O3/FeMn2O4 NP chains were decorated on the GO sheets in different weight ratios and GO-Fe2O3/FeMn2O4 (1 : 3), GO-Fe2O3/FeMn2O4 (1 : 4), and GO-Fe2O3/FeMn2O4 (1 : 5) nanocomposites, which were respectively named S1, S2, and S3, were finally produced. The microwave attenuation performance of all samples was investigated based on their EM parameters. The results demonstrated the superior attenuation ability of S1 and S2 in terms of reflection loss and absorption bandwidth. The minimum reflection losses (RLmin) for S1 and S2 reached over -85 dB and -88 dB and at the rest of the frequency band, the RL varied from -10 dB to -40 dB for samples thicker than 2.4 mm. The effective bandwidth (RL ≤ -10 dB) was 10 GHz, which covered the entire Ku and X bands for S1, and was -8.3 GHz, which eliminated the entire Ku band and half of the X band, for S2 at 2.4-3.6 mm with matching thicknesses. S3 exhibited a relatively weaker absorption performance. The results confirmed that achieving the maximum EM absorption performance of GO-based composites is guaranteed by optimizing the weight ratio of the decorative material (Fe2O3/FeMn2O4 NPs).