Ce_(2)Fe_(17)N_(3-δ)composites have always been focused on electromagnetic wave(EMW)absorbing field because of their high resonance frequency and magnetic loss.However,the issues of preparation cost and impedance mis...Ce_(2)Fe_(17)N_(3-δ)composites have always been focused on electromagnetic wave(EMW)absorbing field because of their high resonance frequency and magnetic loss.However,the issues of preparation cost and impedance mismatching still limit the industrial conversion and practical application of Ce_(2)Fe_(17)N_(3-δ)composites.In this work,the composites of Ce_(2)Fe_(17)N_(3-δ)with a phosphate insulation layer(Ce_(2)Fe_(17)N_(3-δ)@FePO_(4))were prepared by a newly-developed reduction-diffusion(R/D)and phosphating processes using CeO_(2) as raw mate rials,and their microwave absorption properties were investigated.The composite filled with 30 vol%of the Ce_(2)Fe_(17)N_(3-δ)@FePO_(4) has a minimum reflection loss(RL)of-63 dB and an effective absorption bandwidth(EBW,RL<-10 dB)of 3.83 GHz at a thickness of 1.25 mm in the X-band,and the EBW reaches 5 GHz under 0.98 mm in the Ku-band.This study demonstrates that the Ce_(2)Fe_(17)N_(3-δ)@FePO_(4) composite s with low cost and excellent microwave absorption properties have a significant potential for industrial production and practical applications.展开更多
Fe_(81)Al_(19)Tb_(x)(x=0,0.05,0.1,0.2,0.3,0.4)alloys were prepared by a non-consumable vacuum arc melting technique under an inert argon gas atmosphere.The microstructures of the alloys were studied by X-ray diffracti...Fe_(81)Al_(19)Tb_(x)(x=0,0.05,0.1,0.2,0.3,0.4)alloys were prepared by a non-consumable vacuum arc melting technique under an inert argon gas atmosphere.The microstructures of the alloys were studied by X-ray diffraction(XRD)and scanning electron microscopy combined with an energy dispersive spectroscopy(SEM/EDS).The magnetic properties and magnetostriction coefficients of the alloys were measured by a vibrating sample magnetometer(VSM)and adifferential resistive strain sensor,respectively.The results show that the Fe_(81)Al_(19)alloy consists of a single A2 phase with bcc structure,whereas the Tb doped Fe_(81)Al_(19)alloys are composed of the A2 phase and a small amount of rare earth-rich phase.The doping of the rare earth element Tb makes the Fe_(81)Al_(19)alloy preferentially oriented along with the<100>crystal direction.With the increase of Tb content,the magnetostriction coefficient of the alloy first increases and then decreases.When x=0.1,the magnetostriction coefficient reaches the maximum,which is 146×10^(−6).Compared with the as-cast Fe_(81)Al_(19)alloy(27×10^(−6)),it increases by 441%.The enhanced magnetostrictive properties are mainly attributed to the preferred orientation along<100>of A2 phase of the Tb doped Fe_(81)Al_(19)alloys and lattice distortion caused by the small amount of rare earth atoms entering the Fe-Al alloy lattice.展开更多
基金Project supported by the National Key R&D Program of China (2021YFB3501302)the National Natural Science Foundation of China (51731001)the State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization's Key Research and Development Projects。
文摘Ce_(2)Fe_(17)N_(3-δ)composites have always been focused on electromagnetic wave(EMW)absorbing field because of their high resonance frequency and magnetic loss.However,the issues of preparation cost and impedance mismatching still limit the industrial conversion and practical application of Ce_(2)Fe_(17)N_(3-δ)composites.In this work,the composites of Ce_(2)Fe_(17)N_(3-δ)with a phosphate insulation layer(Ce_(2)Fe_(17)N_(3-δ)@FePO_(4))were prepared by a newly-developed reduction-diffusion(R/D)and phosphating processes using CeO_(2) as raw mate rials,and their microwave absorption properties were investigated.The composite filled with 30 vol%of the Ce_(2)Fe_(17)N_(3-δ)@FePO_(4) has a minimum reflection loss(RL)of-63 dB and an effective absorption bandwidth(EBW,RL<-10 dB)of 3.83 GHz at a thickness of 1.25 mm in the X-band,and the EBW reaches 5 GHz under 0.98 mm in the Ku-band.This study demonstrates that the Ce_(2)Fe_(17)N_(3-δ)@FePO_(4) composite s with low cost and excellent microwave absorption properties have a significant potential for industrial production and practical applications.
基金Project supported by the National Natural Science Foundation of China(51661027)the Natural Science Foundation of Inner Mongolia(2019MS05002,2020MS05075)。
文摘Fe_(81)Al_(19)Tb_(x)(x=0,0.05,0.1,0.2,0.3,0.4)alloys were prepared by a non-consumable vacuum arc melting technique under an inert argon gas atmosphere.The microstructures of the alloys were studied by X-ray diffraction(XRD)and scanning electron microscopy combined with an energy dispersive spectroscopy(SEM/EDS).The magnetic properties and magnetostriction coefficients of the alloys were measured by a vibrating sample magnetometer(VSM)and adifferential resistive strain sensor,respectively.The results show that the Fe_(81)Al_(19)alloy consists of a single A2 phase with bcc structure,whereas the Tb doped Fe_(81)Al_(19)alloys are composed of the A2 phase and a small amount of rare earth-rich phase.The doping of the rare earth element Tb makes the Fe_(81)Al_(19)alloy preferentially oriented along with the<100>crystal direction.With the increase of Tb content,the magnetostriction coefficient of the alloy first increases and then decreases.When x=0.1,the magnetostriction coefficient reaches the maximum,which is 146×10^(−6).Compared with the as-cast Fe_(81)Al_(19)alloy(27×10^(−6)),it increases by 441%.The enhanced magnetostrictive properties are mainly attributed to the preferred orientation along<100>of A2 phase of the Tb doped Fe_(81)Al_(19)alloys and lattice distortion caused by the small amount of rare earth atoms entering the Fe-Al alloy lattice.
