Electromagnetic absorption properties of Sn-filled multi-walled carbon nanotubes synthesized by pyrolyzing

Multi-walled carbon nanotubes (MWCNTs) filled with Sn nanocrystals were synthesized by metal-organic chemical vapour deposition at relatively lower pyrolysis temperature. Their electromagnetic parameters and microwave absorbing properties were investigated in the frequency range of 2–18 GHz. An obvious increase in the complex permittivity and electric loss tangent of the Sn-filled MWCNTs has been observed. The dielectric and magnetic properties were significantly improved. The Sn nanocrystals encapsulated in MWCNTs modify the electromagnetic parameters of the MWCNTs. The variation of the normalized input impedance induces the enhancement of absorbing properties. The modified MWCNTs exhibit much broader absorbing bandwidth and larger reflectivity than those of unfilled MWCNTs. The calculated results indicate that the Sn-filled MWCNTs have excellent absorbing properties and potential applications in thin thickness and light weight microwave absorbers.