Effect of Fe Substitution on Magnetic Properties and Radar Wave Absorption of the $\mathbf{Y}_{\mathbf{2}}\mathbf{Co}_{\mathbf{17}}$ Rare Earth Soft Magnetic Alloy

The rapid development of information technology leads a demand for high frequency soft magnetic materials with exceptional radar wave absorption properties. A new magnetic material with superior radar wave absorption is explored in this paper. we explored the preparation of $\mathrm{Y}_{2}\text{Co}_{17-x}\text{Fe}_{x}\ (x=0.0,1.0,2.0,3.0)$ alloy powders using yttrium oxide as a raw material by a low-cost and short preparation cycle reduction-diffusion process. The crystal structure, intrinsic magnetic properties, high frequency magnetism and radar wave absorption of $\mathrm{Y}_{2}\text{Co}_{17-x}\text{Fe}_{x}(x=0.0, 1.0,2.0,3.0)$ were investigated. These compounds have a perfect magnetic repair of $\mathrm{Y}_{2}\text{Co}_{17}$ and enable the improvement of the overall magnetic properties of $\mathrm{Y}_{2}\text{Co}_{17-x}\text{Fe}_{x}\ (x=0.0,1.0,2.0,3.0)$ compounds. The $\mathrm{Y}_{2}\text{Co}_{17-x}\text{Fe}_{x}$ /Polyurethane (PU) $(x=0.0, 1.0,2.0,3.0)$ absorbers were divided in detail using the zero-reflection mechanism. The results show that all $\mathrm{Y}_{2}\text{Co}_{17-\mathrm{x}}\text{Fe}_{x}/\text{PU}(x=0.0,1.0,2.0,3.0)$ absorbers have excellent absorption performance (reflection loss RL is less than -85 dB); in addition, $\mathrm{Y}_{2}\text{Co}_{15}\text{Fe}_{2}/\text{PU}$ absorbers and $\mathrm{Y}_{2}\text{Co}_{14}\text{Fe}_{3}/\text{PU}$ absorbers are superior candidates for S-band materials. In particular, the perfectly matched frequency $f_{\mathrm{p}}$ of the modulated $\mathrm{Y}_{2}\text{Co}_{14}\text{Fe}_{3}/\text{PU}$ absorber is shifted to the L-band (1–2 GHz) where early warning radars are located. The $\mathrm{Y}_{2}\text{Co}_{14}\text{Fe}_{3}/\text{PU}$ absorber has an effective absorption bandwidth of 300 MHz (1.5-1.8 GHz) at a thickness of 5.230 mm. It can also absorb the full L-band at -4 dB, which has rarely been reported.