Preparation of carbon/nickel composites by magnetron sputtering and study on electromagnetic shielding effectiveness

Abstract

A pure nickel film and a carbon/nickel (C/Ni) composite film were produced using radio frequency magnetron sputtering. The structure of the films was regulated by adjusting the sputtering power and the time allocation of sputtering nickel and graphite targets. Furthermore, a scanning electron microscope, an x-ray diffractometer, and a Raman spectrometer were employed for sample characterization. The results demonstrated that the thickness of the pure nickel film and C/Ni composite film with a total deposition time of 60 s was between 44.96 and 65.31 nm. The nickel film exhibited preferential growth along the crystal plane (111), and the structure of carbon materials was in the second stage of the three-stage model known as “amorphization trajectory of graphite.” The prepared films’ electromagnetic interference shielding effectiveness (EMI SE) in the X-band was investigated using a vector network analyzer. It was observed that the C/Ni composite film with a thickness of 44.96 nm demonstrated a superior EMI SE with a maximum value reaching 21 dB. The EMI SE of the C/Ni composite film can reach the same performance and even exceed that of the pure nickel film obtained at the power of 200 W for 60 s in certain frequency segments. In conclusion, the pure nickel film can be replaced by C/Ni composite film prospectively due to their excellent EMI SE along with advantages such as reduced thickness, lighter weight, and lower cost.