Embedding magnetic 3D carbon skeleton in SiCN ceramics for high-performance electromagnetic shielding

The electromagnetic (EM) characteristics of SiCN-based composite ceramics were adjusted by embedding magnetic 3D carbon skeleton (3D-CS) into SiCN ceramics through electroplating and polymer derivation. The distribution uniformity of carbon conductive networks and magnetic particles in composite ceramics were effectively improved profiting from the scheme adopted in this work. In addition, Ni distributed on CS catalyzed the in-situ formation of carbon nanowires (CNWs) in the matrix, and also coordinated the magnetic properties of the ceramics by reacting with Si to form Ni2Si. Benefiting from the embedding of conductive CS and dual role of Ni, the electromagnetic wave (EMW) absorption rate of composite ceramics was improved, and the electromagnetic shielding (EMS) performance was significantly enhanced. When the electroplating time was fixed at 50 min, the EMS value (SETotal) of the composite ceramics in the entire X-band was greater than 55 dB, indicating that more than 99.999% of EMWs are shielded. Beyond that, composite ceramics have excellent solvent (PH = 1 and PH = 14) resistance performance and are powerful candidates for EMS materials in harsh environments.