A Novel Method to Synthesize Co/Fe(3)O(4) Nanocomposites with Optimal Magnetic and Microwave Performance

The magnetic interactions between neighboring magnetic nanoparticles make the synthesis of nanocomposites made of two kinds of magnetic nanoparticles extremely difficult. In this paper, to achieve an effective nanocomposite of Co and Fe(3)O(4) nanoparticles, a special urchin-like Co nanomatrix was used to prepare the Co/Fe(3)O(4) nanocomposites. The Fe(3)O(4) nanoparticles are evenly embedded into the branches of the C(O) clusters, bringing the two types of particles into close contact and ensuring the optimal magnetic and microwave properties. The electromagnetic (EM) parameters at 1–18 GHz and the magnetic loss tangents can be effectively modulated, and the absorption frequency bands of the EM waves are shifted to the X-Ku bands (8–18 GHz) from the S-C bands (2–8 GHz) after the Fe(3)O(4) nanoparticles are compounded.