Soft magnetic material with high saturation magnetization(Ms)and high resistance(ρ)is vital to improve the power density and conversion efficient of modern electrical magnetic equipment.Yet,increasing Ms is always at...Soft magnetic material with high saturation magnetization(Ms)and high resistance(ρ)is vital to improve the power density and conversion efficient of modern electrical magnetic equipment.Yet,increasing Ms is always at the expense of high resistivity,such as soft magnetic alloys substitute for the ferrite.In this work,the superior comprehensive electromagnetic properties,namely the close association of high saturation magnetization and high resistivity,are combined in a new way in a newly Fe-N based magnetic materials.A high resistance oxide interface engineering was constructed between the conducting ferromagnetic phases in the process of spark plasma sintering(SPS)to achieve superior electromagnetic properties.The ZnO compositeγ’-Fe_(4) N bulk has a maximum resistivity of 220μΩ cm and a Ms of up to 156.02 emu/g,while the TiO_(2)compositeγ’-Fe_(4) N bulk has a maximum resistivity of 379μcm and a Ms of 149.7 emu/g.The research findings offer valuable insights for the advancement of the next generation of soft magnetic materials,which hold significant potential for use in high-frequency,high-efficiency,and energy-saving power equipment applications.展开更多
The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave absorber.However,how to fully exploit its wave-absorbing potential re-mains a thoug...The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave absorber.However,how to fully exploit its wave-absorbing potential re-mains a thought-provoking question.Here,we have synthesized Fe/Fe_(4)N@SiO_(2)nanomagnetic core-shell materials with different Fe/Fe_(4)N ratios by performing nitridation reactions at different temperatures.Then,the flower-like core-shell Fe/Fe_(4)N@SiO_(2)structure was obtained by the etching method.Finally,with the synergy of the excellent magnetic and dielectric losses,an outstanding absorption performance could be achieved with a minimum refection loss(RL min)of−71.31 dB at the matching thickness of 1.4 mm,and the widest effective absorption bandwidth(EAB max)of 6.1 GHz less than−10 dB was realized at 1.16 mm.Moreover,this material also shows a preeminent advance in corrosion resistance to adapt to harsh environments.Hence,this iron nitride flower-like core-shell structure exhibits great potential in microwave absorption in harsh conditions.展开更多
基金supported by National Natural Science Foundation of China(No.52071294),National Key Research and Development Program(No.2022YFE0109800)Natural Science Foundation of Zhejiang Province(No.LY20E020015)Key Research and Development Program of Zhejiang Province(No.2021C01172).
文摘Soft magnetic material with high saturation magnetization(Ms)and high resistance(ρ)is vital to improve the power density and conversion efficient of modern electrical magnetic equipment.Yet,increasing Ms is always at the expense of high resistivity,such as soft magnetic alloys substitute for the ferrite.In this work,the superior comprehensive electromagnetic properties,namely the close association of high saturation magnetization and high resistivity,are combined in a new way in a newly Fe-N based magnetic materials.A high resistance oxide interface engineering was constructed between the conducting ferromagnetic phases in the process of spark plasma sintering(SPS)to achieve superior electromagnetic properties.The ZnO compositeγ’-Fe_(4) N bulk has a maximum resistivity of 220μΩ cm and a Ms of up to 156.02 emu/g,while the TiO_(2)compositeγ’-Fe_(4) N bulk has a maximum resistivity of 379μcm and a Ms of 149.7 emu/g.The research findings offer valuable insights for the advancement of the next generation of soft magnetic materials,which hold significant potential for use in high-frequency,high-efficiency,and energy-saving power equipment applications.
基金supported by the National Natural Science Foun-dation of China(Nos.52071294 and U1809215)Natural Science Foundation of Zhejiang Province(Grant LY20E020015)National Key Research and Development Program(No.2019YFE012862).
文摘The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave absorber.However,how to fully exploit its wave-absorbing potential re-mains a thought-provoking question.Here,we have synthesized Fe/Fe_(4)N@SiO_(2)nanomagnetic core-shell materials with different Fe/Fe_(4)N ratios by performing nitridation reactions at different temperatures.Then,the flower-like core-shell Fe/Fe_(4)N@SiO_(2)structure was obtained by the etching method.Finally,with the synergy of the excellent magnetic and dielectric losses,an outstanding absorption performance could be achieved with a minimum refection loss(RL min)of−71.31 dB at the matching thickness of 1.4 mm,and the widest effective absorption bandwidth(EAB max)of 6.1 GHz less than−10 dB was realized at 1.16 mm.Moreover,this material also shows a preeminent advance in corrosion resistance to adapt to harsh environments.Hence,this iron nitride flower-like core-shell structure exhibits great potential in microwave absorption in harsh conditions.
