Low loss CCTO@Fe3O4/epoxy composites with matched permeability and permittivity for high frequency applications

With the rapid development of science and technology progress, the study and preparation of polymer composite materials with multiple properties has become a hot research topic. In this paper, nano-sized CCTO (CaCu₃Ti₄O₁₂) and CCTO@Fe₃O₄ core-shell nanoparticles were prepared using wet chemical method. The CCTO@Fe₃O₄ nanoparticles were characterized by XRD and SEM. The results suggested that the diameter of CCTO is about 500 nm and a Fe₃O₄ shell layer was deposited on the surface of CCTO particles. The epoxy composites consisting of CCTO and CCTO@Fe₃O₄ fillers were prepared, respectively. The dielectric and magnetic properties of the composites were discussed and analyzed at 10⁸-10⁹ Hz. The results show that the permittivity of the composites decreases with the increasing weight ratio of Fe₃O₄/CCTO, while the permeability was enhanced. The dielectric and magnetic loss tangent were increased because of Fe₃O₄ magnetic shell. All these results suggest that the CCTO@Fe₃O₄/epoxy composite films may be used as an new electromagnetic shielding material.