▎ 摘　　要

The composite of FeNi nanocrystals (size of 10-100nm) decorating reduced graphene oxide (rGO) sheets (FeNi@rGO) is prepared by hydrothermal reaction and hydrogen reduction. Compared with sole FeNi nanocrystals, the FeNi@rGO composite possesses a lower frequency of the optimal reflection loss (RL) and a greatly enhanced RL value. An optimal RL of -26.7dB has been achieved at 4.8GHz by measuring the composite with thickness of 4.55mm, which is attributed to the combination of FeNi with excellent magnetic loss and rGO with outstanding dielectric loss, respectively. Obviously, the FeNi@rGO composite has an enormous potential as a microwave absorbing candidate due to its admirable microwave absorption performance.