Tunable dielectric properties and excellent microwave absorbing properties of elliptical Fe3O4 nanorings

Abstract

Elliptical Fe3O4 nanorings (NRs) with continuously tunable axes that range from 40 nm to 145 nm in length were prepared through a precursor-directed synthetic route to determine the electromagnetic responses generated at 2–18 GHz. The tunability of the dielectric properties of Fe3O4 NRs depends on the long axis rather than on the specific surface area, internal stress, and grain size. Elliptical Fe3O4 NRs exhibit the excellent microwave absorbing properties due to the unique ring-like configuration, which significantly enhances permittivity, multiple scattering, oscillation resonance absorption, microantenna radiation, and interference. These findings indicate that ring-like nanostructures are promising for devising effective microwave absorbers.

Synthesis of Zn(II)-Doped Magnetite Leaf-Like Nanorings for Efficient Electromagnetic Wave Absorption

“…On the other hand, plenty of nanorings build a conductive network for electrons hopping and migrating37, which could lead to increased conductivity and thus contributed enhanced electric polarization38. As previously reported by Tong et al 10. ring-like configuration of Fe 3 O 4 exhibit four effective paths that corresponding to four Debye relaxation processes, as confirmed by Cole–Cole plots.…”

“…Among these materials, magnetite is a good candidate as they present unique electromagnetic (EM) properties6789. The electromagnetic properties of magnetite are very sensitive to their compositions, microstructures, shapes and dimensions101112. In general, the morphology and microstructure will affect the conductivity, electric polarization and magnetic properties of magnetite, which will then influences the complex permeability and permittivity in microwave band.…”

“…Specifically, a lot of attention has been focused on magnetite nanostructures in recent years6789101112. Magnetite nanostructures, including nanoparticles, nanospheres, nanowires, nanorings, nanoporous structures and nanoplatelets, have been prepared by a variety of synthetic methods involving chemical co-precipitation, electrochemical, solvothermal method and iron compound decompositions, etc .…”

“…Magnetite nanostructures, including nanoparticles, nanospheres, nanowires, nanorings, nanoporous structures and nanoplatelets, have been prepared by a variety of synthetic methods involving chemical co-precipitation, electrochemical, solvothermal method and iron compound decompositions, etc . In particular, nanorings have attracted strong interests because of their novel structure and properties101113141516. Jia et al 13.…”

“…Recently, Tong’s group10 investigated the EMA properties of elliptical Fe 3 O 4 nanorings. The coating using Fe 3 O 4 nanorings as fillers presented maximum reflection loss ( RL max ) of −58.9 dB at 17.7 GHz, revealing the superiority of Fe 3 O 4 nanorings for EMA applications.…”