Low-temperature synthesis of a novel diboride ceramic with electromagnetic wave absorption properties

At present, electromagnetic wave (EMW) absorption materials face challenges in terms of high efficiency, strong absorption, and low-cost preparation. Based on the thermodynamic behavior analysis of the initial raw materials and the design of temperature curves, a novel (Mo0.2Zr0.2Ti0.2Nb0.2Ta0.2)B2 high-entropy ceramic with a small amount of oxide impurities was successfully synthesized under low-temperature conditions, using a simple thermal reaction method. Test analysis shows that the material has a two-dimensional nanostructured and excellent EMW absorption performance. Within the wide frequency range of 10.8-18.0 GHz, the reflection loss (RL) values of the samples are all less than - 10 dB. Especially, the minimum RL value (sample thickness 6 mm, at 11.4 GHz) can reach - 36.4 dB (99.9% wave absorption). Its excellent EMW absorption performance is related to its good impedance matching and multiple losses. This work provides a low-temperature preparation method for strong EMW absorption materials, and the performance and composition of the material system are adjustable.