Melt-spun Ce-doped CoSiB alloy ribbons with enhanced EMI shielding properties

The emergence of wireless communication and the increased demand on electronic devices resulted in a new pollution type in the form of stray electromagnetic radiation. Hence, the need on efficient electromagnetic interference (EMI) shielding materials increased in the recent years, particularly in microwave frequencies. To address this demand, the present work involves preparation of CoSiB and Ce-doped CoSiB alloys by rapid solidification and investigation of the materials’ electromagnetic interference (EMI) shielding properties in the microwave frequency range of 8–12 GHz. The major point in this research is the investigation of the effect of Ce doping on the EMI shielding performance. We report that the as-prepared melt-spun CoSiB ribbons were amorphous owing to rapid solidification, as could be expected. The vibrating-sample magnetometer analysis shows that the melt-spun alloys were soft magnetic materials. Regarding the EMI shielding properties, Ce doping was found to be improving the EMI shielding effectiveness. The highest total shielding effectiveness in this work was reached in 1% Ce-containing CoSiB alloy as 28.5 dB at 8 GHz. Importantly, the main contribution to EMI shielding performance was found to be absorption with 19.5 dB at the same frequency. This was ascribed to the increase of the imaginary components of the permittivity and permeability upon doping the CoSiB alloy with Ce.