Magnetic and Microwave-absorption Properties of Graphite-coated (Fe, Ni) Nanocapsules.

The structure, magnetic and microwave-absorption properties of graphite-coated (Fe, Ni) alloy nanocapsules, synthesized by the arc-discharge method, have been studied. High-resolution transmission electron microscopy shows that the nanocapsules have a core/shell structure with (Fe, Ni) alloy as the core and graphite as the shell. All (Fe, Ni) alloy nanocapsules/paraffin composites show good microwave-absorption properties. The optimal reflection loss (RL) was found for (Fe₇₀Ni₃₀)/C nanocapsules/paraffin composites, being −47.84 dB at 14.6 GHz for an absorber thickness of 1.99 mm, while the RL values exceeding −10 dB were found in the 12.4–17.4 GHz range, which almost covers the K_u band (12.4–18 GHz). For (Fe₇₀Ni₃₀)/C nanocapsules/paraffin composites, RL values can exceed −10 dB in the 11.4–18 GHz range with an absorber thickness of 1.91 mm, which cover the whole K_u band. [ABSTRACT FROM AUTHOR]