Microwave Absorption Properties of Carbon Nanocoils Coated with Highly Controlled Magnetic Materials by Atomic Layer Deposition

In this work, atomic layer deposition is applied to coat carbon nanocoils with magnetic Fe3O4 or Ni. The coatings have a uniform and highly controlled thickness. The coated nanocoils with coaxial multilayer nanostructures exhibit remarkably improved microwave absorption properties compared to the pristine carbon nanocoils. The enhanced absorption ability arises from the efficient complementarity between complex permittivity and permeability, chiral morphology, and multilayer structure of the products. This method can be extended to exploit other composite materials benefiting from its convenient control of the impedance matching and combination of dielectric-magnetic multiple loss mechanisms for microwave absorption applications.