N-doped magnetic carbon nanosheets for broad, strong, stable and thin microwave absorption properties

The novel magnetic carbon nanocomposite, in which N-doped onion-like carbon encapsulated FeNi nanoparticles are embedded into N-doped carbon nanosheets, are prepared for realizing "broad, strong, stable and thin" microwave absorption behaviors. Good impedance match between magnetic FeNi nanoparticles and dielectric carbon and the large attenuation capability accompanied with strong dielectric loss ability induced by interfacial polarization loss, defect dipole polarization loss, Debye relaxation loss, conductive loss and magnetic loss originating from natural/exchange resonance and eddy current loss ensure the good microwave absorption ability. This nanocomposite exhibits the minimal reflection loss value of –27.62 dB at 4.72 GHz and the effective absorbing bandwidth of 5.76 GHz (covering 12.24–––18 GHz) at 1.9 mm and the peak of reflection loss basically locates at −21.62 dB- −27.62 dB from 1.7 mm to 5.0 mm.