【摘要】 系统地研究了纳米晶FeB合金颗粒的微波磁性.样品由机械合金化方法制备,X射线衍射实验表明合金颗粒是由尺寸约为10 nm左右的纳米微晶组成的.对FeB合金系列样品进行直流及微波磁性测量,结果表明:(1)纳米晶FeB合金颗粒的饱和磁化强度σS随B含量增加而单调下降.(2)FeB合金颗粒的磁损耗μ″,在B含量约为5at.%时达到最大值,其有效复数磁导率为μ=3.06-j3.44,相应的内禀磁导率达μi=5.67-j12.11,当B含量超过10at.%时,磁损耗μ″显著降低.(3)磁损耗μ″的峰值频率随B含量的增加,基本呈下降趋势.通过上述研究,我们得出如下结论:(1)合理地选择纳米晶FeB合金颗粒的成分,可以有效地提高磁损耗μ″.(2)金属间化合物FeB相的出现,对材料的微波磁性将产生不利影响.更多还原

【Abstract】 The systematic and detailed study has been carried out on the magnetic properties of nanocrystalline FeB alloys.The samples are prepared by mechanic alloying method and grain size are analyzed by X-ray diffraction measurements.It is found that alloy particles are composed of nano-sized granules of approximately 10 nm.The magnetic measurements in the static and microwave frequency regime on a series of FeB alloy samples indicate that:(1) the specific saturation magnetization σS of FeB alloy grain decreases with B content.(2) magnetic dissipation reaches a maximum value at B concentration around 5at.%,and the effective magnetic permeability and intrinsic magnetic permeability take the value μ=3.06-j3.44 and μi=5.67-j12.11,respectively,plus further increase in B content beyond 10at.% brings about rapid decrease in magnetic dissipation.(3)the frequency corresponding to the peak value of magnetic dissipation generally decreases with B concentration.Based on above observations,we conclude that:(1) component optimization in nanocrystalline FeB alloys is of vital importance in enhancing the magnetic dissipation.(2) the occurrence of intermetallic FeB phase must be avoided since it is unfavorable to the magnetic dissipation.更多还原