In-situ construction of volcanic rock-like structures in Yb₂O₃ modified reduced graphene oxide and their boosted electromagnetic wave absorbing properties

Creating porous structures is a practical method for enhancing the impedance matching and interfacial polarization of dielectric materials, which in turn leads to improved electromagnetic (EM) wave absorption performance. However, the use of nanoparticles, nanorods, and two-dimensional materials to construct a simple porous structure typically has a minor effect on the EM parameters and interface polarization. To improve impedance matching and reduce the reflection of EM waves while simultaneously enhancing interfacial polarization, a more rational structure for dielectric materials is desired. Herein, a ytterbium oxide/reduced graphene oxide (Yb₂O₃/rGO) composite with a volcanic rock-like structure is proposed to exhibit outstanding impedance matching and loss capacity and achieve high EM wave performance. The addition of Yb₂O₃ is utilized to induce the formation of porous structures with varying morphologies. Yb₂O₃ not only significantly improves the polarization loss but also facilitates volcanic rock-like structure construction, thus improving the EM wave performance. As a result, the Yb₂O₃/rGO composites with a volcanic rock-like structure exhibit outstanding EM absorption performance, including three-band absorption (C, X, and Ku bands), as evidenced by their minimum reflection loss (RL_min) of −57.2 dB (equivalent to 99.9999% effective absorption) at 11.6 GHz when the matched thickness is 2.1 mm and an effective absorption bandwidth (EAB) of 4.2 GHz. Simulations in the CST microwave studio further validate the benefits of the composite's unique structure, which shows a radar cross-section (RCS) reduction value of up to 38.1 dB m². This work offers valuable insights for the development of next-generation EM wave absorption materials through the implementation of a well-designed and distinctive structure.