Range of magnetic correlations in nanocrystalline soft magnets.
Range of magnetic correlations in nanocrystalline soft magnets.
复制标题
纳米晶软磁体中的磁关联范围。
DOI：
10.1103/physrevlett.91.267204
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发表时间：
2003
影响因子：
8.6
通讯作者：
J. Weissmüller
中科院分区：
文献类型：
--
作者：
A. Michels;R. N. Viswanath;J. Barker;R. Birringer;J. Weissmüller
利用小角中子散射数据测定的自旋偏差相关函数，得到了纳米晶电沉积Co和Ni中静态铁磁相关的磁场依赖关系。该方法产生了一个相关长度l(C)，这是磁化分布中不均匀性的空间程度的度量。相关长度在很大程度上取决于外加磁场，其值从低磁场下纳米晶Co的94 nm到饱和时的约15 nm不等。l(C)的结果表明，Co中自旋系统不均匀性的主要来源是单个晶体的各向异性场，而Ni中自旋无序性的主要来源是孪晶缺陷或晶界缺陷核。
We have obtained the magnetic field dependence of static ferromagnetic correlations in nanocrystalline electrodeposited Co and Ni by means of the correlation function of the spin misalignment, determined from small-angle neutron scattering data. The approach yields a correlation length l(C), which is a measure for the spatial extent of inhomogeneities in the magnetization distribution. The correlation length depends strongly on the applied magnetic field with values ranging from 94 nm in nanocrystalline Co at low fields to about 15 nm at saturation. The results for l(C) indicate that in Co the main source of nonuniformity in the spin system is the anisotropy field of each individual crystallite, whereas in nanocrystalline Ni the main sources of spin disorder originate from twin faults or from the defect cores of grain boundaries.