由单一还原剂 NaH_2PO_2或 NaH_2PO_3与 KBH_4的复合还原剂分别在类镍溶液中获得 Ni-Fe-P 以及 Ni-Fe-P-B 合金膜,研究了这些新型合金膜的磁性。结果发现,铁磁性元素 Fe 含量增加导致原子平均磁矩及饱和磁化强度 Ms 增大;结构为非晶态...由单一还原剂 NaH_2PO_2或 NaH_2PO_3与 KBH_4的复合还原剂分别在类镍溶液中获得 Ni-Fe-P 以及 Ni-Fe-P-B 合金膜,研究了这些新型合金膜的磁性。结果发现,铁磁性元素 Fe 含量增加导致原子平均磁矩及饱和磁化强度 Ms 增大;结构为非晶态的合金膜具有较优的矫顽力 Hc 值;合金膜磁滞回线出现较低的矩形比说明化学镀制备态样品不够均匀;热处理温度高于400℃后,合金膜的饱和磁化强度连续减小,矫顽力急剧增大;同时,镀层的均匀性明显得到改善。展开更多
An Fe-based nanocrystalline alloy powder is important for application in microwave absorption,and the particle size has a critical impact on the electromagnetic microwave parameters.Therefore,it is necessary to study ...An Fe-based nanocrystalline alloy powder is important for application in microwave absorption,and the particle size has a critical impact on the electromagnetic microwave parameters.Therefore,it is necessary to study further the effects of the particle size on such parameters and improve the microwave absorption performance of Febased nanocrystalline powers.In this study,Fe-B-P particles were prepared through a synthetic approach consisting of an aqueous chemical reduction and a ball milling treatment.We investigated the effects of ball milling on the microstructure and electromagnetic properties of Fe-B-P particles.The experimental results indicate that the Fe-B-P particles synthesized through an aqueous chemical reduction are amorphous spheres.Fe-B-P particles with an original particle size of 200-1200 nm can be milled into an irregular shape with the size reduced to\500 nm after 0.5 h of ball milling,and subsequently,the particles become smaller with increases in the milling time,with traces of Fe2O3 generated on the particle surface.The results of the Mo¨ssbauer spectra show that a portion of the small particles demonstrate a superparamagnetic property.The volume proportions of the superparamagnetic component increase from 13.1 to 15.8%as the treatment time increases.We measured the permittivity and permeability spectra of Fe-B-P particles within the frequency range of 2-18 GHz.The reflection loss(RL)is-10 dB for an absorber thickness of 1.7-5.0 mm.The RL is-20 dB for an absorber thickness of 1.9-2.7 mm.The microwave absorption properties of samples with the same thickness are improved with an increase in the treatment time and are shifted to a higher frequency,which will broaden the bandwidth of the absorption as well.展开更多
文摘由单一还原剂 NaH_2PO_2或 NaH_2PO_3与 KBH_4的复合还原剂分别在类镍溶液中获得 Ni-Fe-P 以及 Ni-Fe-P-B 合金膜,研究了这些新型合金膜的磁性。结果发现,铁磁性元素 Fe 含量增加导致原子平均磁矩及饱和磁化强度 Ms 增大;结构为非晶态的合金膜具有较优的矫顽力 Hc 值;合金膜磁滞回线出现较低的矩形比说明化学镀制备态样品不够均匀;热处理温度高于400℃后,合金膜的饱和磁化强度连续减小,矫顽力急剧增大;同时,镀层的均匀性明显得到改善。
基金supported by the National Natural Science Foundation of China (Nos. 51401049, U1704253)Natural Science Foundation of Zhejiang Province (No. LR18E010001)Key Research and Development Program of Zhejiang Province (No. 2019C01121)
文摘An Fe-based nanocrystalline alloy powder is important for application in microwave absorption,and the particle size has a critical impact on the electromagnetic microwave parameters.Therefore,it is necessary to study further the effects of the particle size on such parameters and improve the microwave absorption performance of Febased nanocrystalline powers.In this study,Fe-B-P particles were prepared through a synthetic approach consisting of an aqueous chemical reduction and a ball milling treatment.We investigated the effects of ball milling on the microstructure and electromagnetic properties of Fe-B-P particles.The experimental results indicate that the Fe-B-P particles synthesized through an aqueous chemical reduction are amorphous spheres.Fe-B-P particles with an original particle size of 200-1200 nm can be milled into an irregular shape with the size reduced to\500 nm after 0.5 h of ball milling,and subsequently,the particles become smaller with increases in the milling time,with traces of Fe2O3 generated on the particle surface.The results of the Mo¨ssbauer spectra show that a portion of the small particles demonstrate a superparamagnetic property.The volume proportions of the superparamagnetic component increase from 13.1 to 15.8%as the treatment time increases.We measured the permittivity and permeability spectra of Fe-B-P particles within the frequency range of 2-18 GHz.The reflection loss(RL)is-10 dB for an absorber thickness of 1.7-5.0 mm.The RL is-20 dB for an absorber thickness of 1.9-2.7 mm.The microwave absorption properties of samples with the same thickness are improved with an increase in the treatment time and are shifted to a higher frequency,which will broaden the bandwidth of the absorption as well.
