Microwave absorption study of composites based on CQD@BaTiO3 core shell and BaFe12O19 nanoparticles

A novel microwave absorbing composite medium for X-band (8 GHz-12GHz) is developed by mixing of core-shell consisting of carbon quantum dots (CQDs) coated barium titanate (BaTiO3) fibers with barium hexaferrite (BaFe12019) nanoparticles. CQDs are synthesized from agricultural waste using lemon peel as precursor material while the low density BaTiO3 fibers are synthesized via electro-spinning technique. The increase in diameter of BaTiO3 fibers as an effect of CQD coating has been confirmed using FESEM technique. The XRD and FTIR analysis of CQD coated BaTiO3 fibers are used to confirm the presence of carbon along with barium titanate. Composites based on BaFe12019 nanoparticles and CQD coated barium titanate (CQD@BaTiO3) fibers were developed by the ball-milling of BaFe12019 nanoparticles with CQD@BaTiO3 in different weight concentrations. The improved electrical permittivity of the BaFe12019 and CQD@BaTiO3 composites resulted in the increased reflection loss due to better impedance matching with the free space. The maximum reflection loss of -25.38 dB was achieved for composite containing 85% of BaFe12019 and 15% of CQD@BaTiO3, for a pellet of thickness 2.75 mm. Also, the maximum -10dB bandwidth (90% absorption) of the composite reaches to 2.7 GHz. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A novel microwave absorbing composite medium for X-band has been developed by mixing carbon quantum dots coated barium titanate fibers with barium hexaferrite nanoparticles, resulting in improved reflection loss of -25.38 dB. This composite showed enhanced absorption performance with a maximum -10dB bandwidth of 2.7 GHz.