Constructing Magnetic Iron-Based Core-Shell Structure and Dielectric Nitrogen-Doped Reduced Graphene Oxide Nanocomposite for Enhanced Microwave Absorption Performance

Abstract

A ferromagnetic nanocomposite Fe 3 O 4 @Fe/Fe 4 N/CFe 15.1 -NrGO, which is composed of elemental iron-, iron nitride- and iron carbide-coated ferroferric oxide core-shell structured nanospheres and nitrogen-doped partially-reduced graphene oxide (NrGO), has been successfully prepared by combining an initial hydrothermal processing, subsequent reducing agent impregnation and final solid-state thermal reduction. And then, we investigate the microwave absorption performance of nanocomposite in paraffin dispersion. When the loading mass of Fe 3 O 4 @Fe/Fe 4 N/CFe 15.1 -NrGO is 9.0 wt.% in paraffin dispersion, the minimum reflection loss (RL min ) of microwave is as high as -30.5 dB at the thickness of 1.5 mm, and the corresponding effective absorption bandwidth (EAB<-10 dB) of 4.4 GHz (13.6~18.0 GHz) is the 27.5% of the entirely measuring bandwidth from (2.0~18.0 GHz). The excellent microwave absorbing performances of nanocomposite Fe 3 O 4 @Fe/Fe 4 N/CFe 15.1 -NrGO may be attributed to the following twoaspects: (i) the interfacial polarization of the core-shell structure of spheroidal iron-based constituents and the interface between an iron-based nanosphere and dielectric lamellar NrGO and (ii) a synergistic effect between dielectric properties of lamellar-structured NrGO and the magnetic properties of core-sell structure   .

Keywords: microwave absorbing material, Ferromagnetic nanocomposite, graphene oxide, dielectric loss, magnetic loss