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采用熔体快淬方法制备的[(Fe_(1-x)Co_x)_(0.675)Pt_(0.325)]_(84)B_(16)(X=0.1～0.5)系列纳米晶甩带,通过优化退火热处理后,运用磁力/原子力显微镜(MFM/AFM)研究了Co浓度对样品的晶体与微磁结构的影响.结果表明,甩带的微磁及微晶结构与Co对Fe替代的浓度密切相关.甩带的微磁结构可确定为交换耦合畴结构,由随机分布的黑白相间的点状畴构成,且畴的尺寸约为3～6个其晶粒尺寸的大小.运用Landau-Lifshitz自由能最小化理论解释了纳必晶甩带形成交换耦合畴的机理.甩带的微晶颗粒的直径随着Co含量的增加而变化,但都小于100 nm.具有高矫顽力(_iH_e)样品呈现了更一致、更大的磁畴结构和更均匀、更细小的晶粒结构.平均的畴尺寸与晶粒尺寸的比例(ω/D)可以半定量地表征交换耦合的强度,当x=0.3时ω/D达到最大值,此时交换耦合最强,这与磁性测量的结果完全一致.
A series of nanocrystalline ribbons were prepared by the melt quenching method. The nanocrystalline ribbons were prepared by the optimized After annealing, the effect of Co concentration on the microstructure and micro-magnetic structure of the samples was investigated by using a magnetic force / atomic force microscope (MFM / AFM). The results show that the micro-magnetic and microcrystalline structure of the rejection band is closely related to the concentration of Co substituted by Fe The micro-magnetic structure of the rejection band can be identified as an exchange-coupled domain structure consisting of randomly distributed black and white dotted domains with a size of about 3 to 6 of the grain size.The Landau-Lifshitz free energy The minimization theory explains the mechanism of the formation of exchange-coupled domains in the nanobrystal rejection zone, in which the diameter of the microcrystalline particles in the rejection zone changes with the increase of Co content, but both are less than 100 nm. The samples with high coercivity (_iH_e) A more uniform, larger magnetic domain structure and a more uniform, finer grain structure.The average ratio of domain size to grain size (ω / D) can semi-quantitatively characterize the strength of the exchange coupling, and when x = 0.3 When ω / D reaches the maximum, the exchange coupling is strongest at this time, which is exactly the same with the result of the magnetic measurement.