Design and verification of bionic absorbing metamaterials based on rare earth ions doped nickel-based ferrite

Nickel-based ferrite materials that absorb electromagnetic waves show great promise for protecting against electromagnetic interference. However, conventional materials have drawbacks, such as limited absorption bandwidths and reliance on a single loss mechanism. Therefore, enhancing their overall performance by optimizing composition and structure is essential. In this study, nickel-based ferrites were modified by varying the type and amount of doped rare-earth ions, and the best-performing sample was selected based on its wave-absorption capabilities. The optimal sample, with a thickness of 2.74 mm, achieved a minimum reflection loss of −40.14 dB at 11.60 GHz and an effective absorption bandwidth of 5.83 GHz (10.57-16.40 GHz). Its strong magnetic loss is due to magnetic components, while the improved dielectric loss arises from lattice distortions and structural defects induced by doping. Additionally, a biomimetic honeycomb periodic metamaterial was designed using this material as the absorber. Simulations showed that, at a thickness of 5.5 mm, the metamaterial reached a minimum reflection loss of −22.59 dB at 12.51 GHz and an effective absorption bandwidth of 8.39 GHz (9.61-18.00 GHz). The metamaterial was then physically fabricated, and experimental tests confirmed that its performance closely matched the simulations, validating the design and highlighting the material's broad potential for integrated structural-functional applications.