Microwave absorption properties of (1 − x)La0.85Ag0.15MnO3/x graphene (x = 0, 3, and 5 wt.%) composites

Abstract

AbstractComposite of (1 − x)La0.85Ag0.15MnO3/x graphene (x = 0, 3, and 5 wt.%) and epoxy resin with a ratio of 4:1 were prepared to investigate the influence of the addition of graphene in (1 − x)La0.85Ag0.15MnO3/x graphene on real and imaginary parts of permittivity, permeability, as well as microwave reflection loss (RL), using a vector network analyzer in the 8–18 GHz of the frequency range. It is found that the value of RL is smaller at x = 3 wt.% (−20.74 dB at 14.85 GHz) and 5 wt.% (−14.81 at 16.50 GHz) compared to at x = 0 wt.% (−8.89 dB at 15.90 GHz). The result indicates that microwave absorption properties significantly improved as a result of the addition of graphene. It is suggested that the addition of graphene enhanced the dielectric loss–related mechanism such as interfacial polarization and conduction loss resulting in an improvement of microwave absorption performance for both x = 3 wt.% and x = 5 wt.% samples. It also shows that the observed enhanced microwave absorption properties may also be influenced by the resistivity of the sample as x = 3 wt.% sample exhibits enhanced microwave absorption properties and the lowest resistivity among the studied samples.