摘要
The design and optimization of one-dimension(1D)magnetic material are of great importance for the energy conversion,storage and spin electron devices,which remain a huge challenge.Herein,1D porous Fe_(3)O_(4) nanotubes(NTs)have been fabricated via a combined process of electrospinning and calcination.In the electrospinning precursors,by regulating the content ratio between two types of polyvinyl pyrrolidone with different molecular weight,porous Fe_(3)O_(4) NTs with vortex-domain configuration have been fabricated.Based on the unique 1D nanotube structure encapsulated with multi-domains,the composite Fe_(3)O_(4) NTs exhibit high complex permeability(μʹ,μʺ)values,and hold both strong magnetic storage and dissipation capacity.Our Fe_(3)O_(4) NTs exhibit excellent microwave absorption(MA)performance with the maximum reflection loss value of−57.1 dB and the efficient absorption bandwidth of 12.0 GHz.The generated magnetic vortices make the crucial contribution to the spin-wave resonance which improves the MA dissipation under high-frequency.Related magnetic flux line distribution and magnetic domain moment were confirmed by the electron holography and micro-magnetic simulation,respectively,providing the deep insight to the microwave absorption mechanism.
基金
supported by the National Natural Science Foundation of China(Nos.51725101,11727807,51672050,61790581,and 22088101)
the National Basic Research Program of China(No.2018YFA0209102)
Infrastructure and Facility Construction Project of Zhejiang Laboratory.
