Synthesis and Micro-Wave Absorption Properties of BiFeO₃ Coated Fe Nanocapsules

Abstract

BiFeO3coated ferromagnetic Fe nanocapsules is synthesized by arc-discharging method. Typical HRTEM images show that the nanocapsules form in a core-shell structure. X-ray photoelectron spectrum (XPS) and X-ray diffraction (XRD) reveal that the core is ferromagnetic Fe, while the shell is BiFeO3/Bi2Fe4O9.The reflection loss R of less than -10 dB was obtained for the whole frequency within the 2-18GHz range by choosing an appropriate layer thickness between 1.0mm and 7.0mm. An optimal reflection loss of -21.5 dB was reached at 10.6 GHz with an absorber thickness of 2.0mm. It is worth noticing that the BiFeO3coated Fe nanocapsules have two absorption peaks below -10 dB at each thickness layer ranging from 4.0nm to 7.0nm, which means the composites nanocapsules absorber simultaneously are able to absorb microwaves in different band of several GHz.

Unusual continuous dual absorption peaks in Ca-doped BiFeO3nanostructures for broadened microwave absorption

“…16 In the BiFeO 3 -coated Fe, the strong microwave absorption properties (RL min ∼ −21.3 dB, QB ∼ 3.6 GHz) were ascribed to the strong natural resonance and multipolarization of the core-shell interface. 17 In the approach for extending the QB, introduction of a magnetic phase into a dielectric material has shown considerable progress, where dual absorption peaks were generally achieved and thus the QB could be essentially enlarged. For typical examples, the as-prepared RGO/Ni heterostructures exhibit dual microwave absorption peaks located at ∼3.5 GHz (RL ∼ −17.2 dB) and ∼12.6 GHz (RL ∼ −17.0 dB) and the gap of insufficient absorption with a width of ∼8.0 GHz was observed between these two peaks.…”

Barium and Yttrium Co-doping in Bismuth Ferrite Nanoparticles to Enhance Microwave Properties

“…A similar phenomenon is observed in Nddoped BFO as well [12], reporting an RL min of −42 dB and BW of 3 GHz. Natural resonance and increased polarization at the interface of the core-shell structure are observed to enhance the absorption in BFO-coated Fe nanocapsules [13]. Manipulation of the phase boundary in coexisting R3c and P4mm phases of Calcium doped BFO is as well performed, reporting an enhanced microwave absorption [14].…”