Core–Shell Chain-Like Cu@Ni Composite with Dual Absorption Peaks to Improve Microwave Absorption Properties.

Core–shell Cu@Ni chains were successfully synthesized through a mild hydrothermal reaction. The morphology, structure and microwave electromagnetic properties of the composite were then characterized by X-ray diffraction, energy-dispersive spectroscopy, scanning electron microscopy and vector network analysis. The formation mechanisms of the core–shell structure and one-dimensional chains were ascribed to the varying redox potentials of Cu and Ni ions and the magnetic dipole–dipole attraction. Furthermore, a minimal reflection loss (RL) of −20.7dB was observed at 9.6GHz with a thickness of 2.0mm and the effective absorption (≤10dB, 90% microwave attenuation) bandwidth can be adjusted between 5.2GHz and 16.6GHz for the thin absorber thickness of 2.0–4.0mm. The novel core–shell chain-like Cu@Ni alloy can be used as a promising absorbing material because it shows numerous features such as thin thickness, strong absorption, low cost and lightweight. The core–shell chain-like Cu@Ni composite shows dual absorption peaks 9.6 GHz and 11.1 GHz at an absorber thickness of 2mm. A minimal reflection loss of –20.7 dB was observed at 9.6 GHz and the effective absorption (<–10 dB, 90% microwave attenuation) bandwidth can be adjusted between 5.2 and 16.6 GHz for the thin absorber thickness of 2.0–4.0 mm. [ABSTRACT FROM AUTHOR]