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https://doi.org/10.1007/s11664-020-08460-9  2020 The Minerals, Metals & Materials Society

Enhanced Microwave Absorption Performance of SWCNT/SiC Composites SAMARJIT SINGH,1 ABHISHEK KUMAR and DHARMENDRA SINGH2

,1,3

1.—Department of Applied Mechanics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, India. 2.—Department of Electronics and Computer Engineering, Indian Institute of Technology Roorkee, Roorkee, India. 3.—e-mail: [email protected]

The present work emphasizes the microwave absorption performance of single-walled carbon nanotube (SWCNT)/SiC composites prepared by mechanically mixing the components, i.e., SWCNT and SiC in desired weight fractions using a cost-effective and simple ball-milling route. The microwave absorption results reveal that the integration of SiC with a small weight fraction of SWCNT exhibited an improved absorption performance in the Ku band compared to pristine SiC. The SWCNT/SiC composite with 2.5 wt.% SWCNT exhibited a superior microwave absorption behavior with a minimum reflection loss of  37.11 dB and <  10 dB absorption bandwidth of 4.38 GHz for the absorber thickness of 2 mm. The microwave absorption efficiency of SWCNT/SiC composites was also measured corresponding to  10 dB, which is equivalent to 90% microwave absorption when evaluating the absorption performance. A maximum microwave absorption efficiency of 18.95 dB GHz/ mm was observed for the composite with 2.5 wt.% SWCNT dispersion compared to 3.4 dB GHz/mm for pristine SiC. Enhanced microwave absorption characteristics for SWCNT/SiC composites may be attributed to various absorption mechanisms, such as dipole polarization, multiple scatterings, multiple reflections, conductive loss, interfacial polarization, and defect-induced dipole polarization. The microwave absorption results of SWCNT/SiC composites indicate that they may serve as encouraging thin thickness candidates with superior microwave absorption for application in the Ku band.

(Received June 25, 2020; accepted August 28, 2020)

S. Singh, Kumar and D. Singh

Graphic Abstract

Key words: SiC, SWCNT, microwave absorption, reflection loss, interfacial polarization, multiple reflections

INTRODUCTION Electronic equipment has become the backbone of modern society, covering every walk of life, encompassing civil, military, and healthcare systems.1,2 This upsurge in the usage of electronic gadgets has led to significant growth in the electronics sector. However, the extensive use of electronic systems has led to electromagnetic pollution problems.3,4 The interference of the microwave signals of various electronic systems affects the operational functionality of telecommunication and electronic appliances. The electromagnetic pollution problem not only interferes with the proper functioning of electronic appliances but it also poses serious health issues by causing various life-threatening diseases.5 The severity of the situation has given rise to the need to develop high-performance microwave absorbing materials to tackle the electrom