Preparation And Microwave Absorption Properties Of BaTiO₃/BN（C）/Magnetic Transition Metal Nanoparticles

BaTiO3has a favorable ferroelectric and piezoelectric properties, lofty dielectricconstant and high anti-pressure, there is a typical ceramic material of electromagneticloss properties. The ferroelectric polarization of BaTiO3can cause the dielectric lossand the ferromagnetic polarization of BaTiO3can cause the magnetic loss. It has greatapplication potential in the field of wave absorption materials.Based on the above reasons, combining the single-phase BaTiO3withferromagnetic BN-Ni particles into absorption materials with the multiferroiccomposite nanocapsule structure are designed in this paper. Taking advantage ofBaTiO3dielectric dispersion characteristics can regulate the dielectric dispersioncharacteristics of magnetic nanocapsules and the absorption properties in differentband, broaden absorption band, and improve the absorption properties of nanocapsule.First use plasma DC arc discharge method, by changing the target component,reaction atmosphere composition and proportion and control the arc current. BN/Ninanocapsules were prepared successfully. The preparation of nanocapsule diameter of30-100nm, with Ni as the core, BN as the shell of the core-shell structure. The use ofliquid phase hydrolysis precipitation-DC arc method combined with the sampleprepared with Ni as core, BN as the middle layer, the outer layer of the BaTiO3coating structure. Analysis shows that the microwave performance of DC arc structure:preparation of BN/Ni nanocapsule powder, the maximum reflection loss in thefrequency of14.2GHz was-28dB, corresponding to the thickness of6mm, and thereflection absorption coefficient in the-10dB below is the frequency band range of8.0-10GHz(thickness3mm)and13.5-14.1GHz(6mm thickness); The use of liquidphase hydrolysis precipitation-DC arc plasma preparing nanometer powder ofmaximum reflection loss at7.61GHz up to-32dB.The second part of this paper studies the use of DC arc method for preparing Ccoated Fe nanocapsules, the particle size is20-100nm, the outer shell layer wasdisordered carbon, the inner layer is a core-shell structure of Fe, the shell thickness ofabout5-10nm. The maximum reflection loss of BaTiO3/C/Fe nanopowders prepared at the frequency of9.19GHz was-37dB, corresponding to the thickness of2.1mm, the10.3GHz reflection loss reached-35dB, corresponding to a thickness of1.7mm. Andthe reflection absorption coefficient in the band below-10dB in the range8-16GHz.The preparation with BaTiO3as the outermost C as the middle layer Fe compositenanocapsule nuclear double shell structure by sol gel-DC electric arc method. Themicrowave absorbing performance is good. The maximum reflection loss in thefrequency of6.97GHz was-37dB, corresponding to the thickness of2.1mm.The experimental results show that, when the incident electromagnetic wavefrequency in the range of2-18GHz, the liquid phase hydrolysis precipitation-DC arcdischarge method or sol-gel DC arc method combined with the prepared sample,absorption performance than the use of DC arc samples prepared by microwave. Thecoating thickness is different, the absorption peak and wide frequency band are thecoefficient of variation, were slightly to the low-frequency band mobile. Therefore,the regulation of composite material preparation method using multi BaTiO3coveringdifferent nanocapsules can realize electromagnetic parameters of single phase BaTiO3on BN/Ni and C/Fe structure, multiphase structure the system so that each phase inthe electromagnetic coupling of nanocoating, greatly improving the as preparedsamples of dielectric loss and magnetic loss, it has a good microwave absorbingproperties.