Microwave absorption performance of reduced graphene oxide with negative imaginary permeability

Abstract In this work, reduced graphene oxide (RGO) aerogels of various pore sizes were fabricated by hydrothermal and lyophilizing processes and their influence on microwave absorption via optimization of electrical conductivity and permittivity was studied. At a fixed aerogel filler loading of 1.7 wt.%, both the electrical conductivity and permittivity of the RGO/wax composites were first increased and then decreased by increasing the pore size in the RGO aerogels. Impressively, when electrical conductivity is sufficiently high, the negative imaginary part of the permeability ( ) can be observed at the same time. This work provides an effective method of fabricating highly efficient electromagnetic wave absorbents while optimizing dielectric loss and impedance matching behaviors, as well as direct evidence on the understanding of the negative phenomenon.