Microstructural evolution and electromagnetic wave absorbing performance of single-source-precursor-synthesized SiCuCN-based ceramic nanocomposites

Copper-containing single-source precursors for preparation of SiCuCN-based ceramic nanocomposites were successfully synthesized the first time using polysilazane, copper acetate monohydrate and 2-aminoethanol via nucleophilic substitution reaction at Si centers polysilazane. The synthesis process, polymer-to-ceramic transformation high-temperature microstructural evolution prepared ceramics characterized. Dielectric properties electromagnetic wave (EMW) absorbing performance investigated as well. results show that finishes ca.900℃, Cu nanoparticles are homogeneous distributed in SiCN matrix, forming a SiCN/Cu nanocomposite. After annealing 1200℃, completely transform into Cu3Si. Interestingly, thermal stability can be strongly improved by increasing free carbon content, so part metallic detected annealed even 1300℃, SiCN/Cu/Cu3Si/C Compared with SiCN, exhibit enhanced dielectric which outstanding EMW performance. minimum reflection coefficient (RCmin) 1300 ºC achieves -59.85 dB sample thickness 1.55 mm, effective absorption bandwidth broadens to 5.55 GHz 1.45 mm. attributed an in situ formed unique network was constructed Cu3Si connected ring-like ribbons within matrix.