MOF-derived bundle-like Nd2O3/Fe@C nanocomposite for efficient microwave absorption

Metal–organic framework (MOF) derivatives have emerged as promising candidates for designing lightweight, high-performance electromagnetic wave absorption (EMWA) materials owing to their tunable porosity, compositional diversity, and structural flexibility. In this study, a hybrid material (Nd/Fe-MOF) comprising Nd- and Fe-based MOFs was constructed via ion-exchange engineering based on an MOF-plus-MOF strategy, involving partial exchange between Nd³⁺ and Fe³⁺ ions. The subsequent pyrolysis of Nd/Fe-MOF yielded a particle-decorated bundle-like Nd 2 O 3 /Fe@C nanocomposite, which exhibited an exceptional EMWA performance with a minimum reflection loss (RL min )of −60.13   dB and an effective absorption bandwidth (EAB) of 5.0   GHz at a thin thickness of 1.8   mm. Moreover, Nd 2 O 3 /Fe@C also displayed an enhanced absorption with an EAB of 2.1   GHz (5.2–7.3   GHz) at low-frequency C band. This outstanding EMWA behavior can be attributed to the optimized impedance matching induced by the introduction of Nd 2 O 3 , and the prolonged propagation paths of EMW caused by the bundle-like structure. In order to present the practical application, CST simulation showed that the reduction value of radar cross section (RCS) of Nd 2 O 3 /Fe@C could reach up to 32.6   dB   m² compared to the pure perfect electric conductor (PEC) substrate. Therefore, this study demonstrates the feasibility of employing ion-exchange engineering for the optimization of electromagnetic parameters and the subsequent development of high-efficiency rare earth–based absorbers.