Recent Advances in Graphene Oxide-Ferrite Hybrid Framework as Radar Absorbing Material

Abstract

The excessive usage of electronic devices results in tremendous increase in electronic pollutions such as electromagnetic interference (EMI) and electronic noise. In order to safeguard the electronic equipments from excessive electromagnetic waves, microwave absorbing/electromagnetic interference shielding materials has been continuously explored. These EMI shielding materials can be layered on military aircrafts, missiles, tanks, etc., so that they cannot be detected by the RADAR. Blocking of electromagnetic (EM) waves can be achieved by using shielding material such as conductive or magnetic. Owing to their superior electric, mechanical, thermal properties and large aspect ratio, graphene has gained much importance as microwave absorbing material. Electromagnetic shielding efficiency of graphene is 135 dB. On the other hand, the ferrites such as hexaferrite/spinel have attracted researchers as radar absorbing materials because these materials possess good magnetic as well as dielectric properties. However, neither ferrites nor carbon-containing materials (graphene, reduced graphene oxide, carbon black or carbon nanotubes) independently meet the EMI shielding properties such as large absorption peak, thin absorption layer and wide frequency range. To achieve high EM absorption properties, a material based on graphene oxide-ferrite nanocomposite has been synthesized and extensively investigated. As complex permittivity, permeability of material decides the EM absorption properties. The electric loss in composite is achieved by substituting losing fillers such as graphene/reduced graphene oxide to a matrix, and magnetic loss is provided by hexaferrite or spinel ferrite by means of big hysteresis attenuation in a matrix. This chapter reviews the research conducted in the field of microwave absorbing materials. The focus will be on the uniqueness and universality of graphene oxide-ferrite nanocomposites versus other unconventional materials in terms of materials chemistry and physics, electronic, magnetic characteristics, synthesis strategies and selected applications in an electromagnetic interference shielding.