Microwave absorption properties of Sr2FeMoO6 nanoparticles

The microwave absorption properties of nanosized double perovskite Sr2FeMoO6 and epoxy resin composites were investigated in the frequency range of 2–18 GHz using the coaxial method. The Sr2FeMoO6 composites with an optimal 20 wt% epoxy resin showed a strong electromagnetic attenuation of −49.3 dB at 8.58 GHz with a matching thickness of 2.15 mm. Moreover the optimum absorption frequency at which the reflection loss is less than −20 dB, which corresponds to 99% reflection loss of the incident microwave, is from 5.7 to 13.2 GHz with the matching thickness ranging from 3.0 to 1.5 mm. The excellent microwave-absorption properties are a consequence of a proper electromagnetic match due to the existence of the insulating matrix of anti-site defects and anti-phase domains, which not only contribute to the dielectric loss but also to the reduced eddy current loss.