Multifactor optimization of microwave absorption properties in Co/CNT@SiC composites via temperature-driven structural and compositional modulation

Abstract

Co particle-loaded carbon nanotube (CNT)–SiC nanowire composites were prepared by heat polymerization and carbonization processes. By modulating the pyrolysis temperature to achieve the co-construction of the multilevel structure of the composites, the dielectric polarization and interfacial polarization effects are enhanced, and the introduced Co magnetic particles increase the permeability of the materials and improve the magnetic loss mechanism. Furthermore, the Co nanoparticles loaded on the CNTs alleviate the problem of Co magnetic particle agglomeration. The microwave absorption properties of the composites are optimized when the heat treatment temperature is 900 °C, with the minimum value of reflection loss (RL_min) reaching −64.16 dB at d = 2.28 mm and f = 11.2 GHz. This work provides referable research ideas for synthesizing wave-absorbing materials under high-temperature conditions and broadens the application scope of ceramic matrix composites.