Fluorescence and microwave-absorption properties of multi-functional ZnO-coated α-Fe solid-solution nanocapsules

Fluorescence (FL) and microwave-absorption properties of multi-functional alpha-Fe solid-solution nanocapsules have been investigated. High-resolution transmission electron microscopy and x-ray photoelectron spectroscopy analysis show that the nanocapsules have a shell/core structure with alpha-Fe solid-solution nanoparticles as the core and amorphous ZnO as the shell. The nanocapsules are ferromagnetic at room temperature. There is a tendency to redshift for the peak at 388 nm in the FL spectra as the Zn concentration decreases. The in-depth study of relative permittivity and permeability reveals that the ZnO-coated alpha-Fe solid-solution nanocapsules exhibit excellent microwave-absorption properties, because of a proper electromagnetic match in the microstructure, strong natural resonances and dipolar polarization mechanisms.