Facile synthesis and novel microwave electromagnetic properties of flower-like Ni structures by a solvothermal method

Flower-like Ni structures composed of leaf-like flakes were synthesized through a facile solvothermal approach independent of surfactants or magnetic force. The evolution of the morphology was closely related to the variation of NaOH and volume ratios of ethylene glycol to water. The microwave absorbing properties of the flower-like Ni wax-composite were evaluated based on the complex permittivity (er = e′ − je″) and permeability (µr = µ′ − jµ″). The Ni wax-composite exhibited excellent microwave absorption performances with a minimum reflection loss of −46.1 dB at 13.3 GHz, corresponding to a matching thickness of 2.0 mm. In particular, the absorption bandwidth of RL below −10 dB was 3.6 GHz (11.7–15.3 GHz). The attenuation of microwave could be attributed to the dielectric loss and unique flower-like structure.