Hollow nanostructures of metal oxides as efficient absorbers for electromagnetic interference shielding

Abstract

Large numbers of organic as well as inorganic materials, with solid morphologies are investigated for electromagnetic interference (EMI) shielding. It is shown that the entrapping of electromagnetic waves within a cavity of hollow structures of typical metal oxides, such as Cu2O increases the shielding effectiveness. The performance of hollow structures is compared with that of solid particles. It is shown that hollow structures lead to the absorption of EM waves on exterior surfaces as well as with-in the cavity. This makes their use as efficient buffers for EM waves in next generation EMI shields or absorbers quite feasible. This paper also discusses the observed conductivity variation in hollow structures. As the hollow structures are also much lighter than their solid counterparts, it gives them additional advantage for large-scale use.