Bulk and element-specific magnetism of medium-entropy and high-entropy Cantor-Wu alloys
Bulk and element-specific magnetism of medium-entropy and high-entropy Cantor-Wu alloys
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DOI：
10.1103/physrevb.102.174405
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发表时间：
2020-11-05
影响因子：
3.7
通讯作者：
Dugdale, S. B.
中科院分区：
文献类型：
--
作者：
Billington, D.;James, A. D. N.;Dugdale, S. B.
磁康普顿散射，X-射线磁圆二色光谱，和体磁强计测量进行一组中等（NiFeCo和NiFeCoCr）和高熵（NiFeCoCrPd和NiFeCoCrMn）Cantor-Wu合金。由磁康普顿散射确定的体自旋动量密度是显著各向同性的，这是电子准粒子的无序散射对电子结构的涂抹的结果。非零的X射线磁性圆二色性信号观察到每个合金中的每个元素，表明在人口的多数和少数自旋状态意味着有限的磁矩的差异。当Cr被包括在固溶体中时，Cr的自旋矩是明确地反平行于总磁矩，而对于Mn观察到一个非常小的磁矩，尽管计算表明一个大的磁矩。一些显着的差异之间观察到的实验体和表面的磁矩。尽管缺乏定量的协议，元素特定的表面磁矩似乎是定性合理的。
Magnetic Compton scattering, x-ray magnetic circular dichroism spectroscopy, and bulk magnetometry measurements are performed on a set of medium- (NiFeCo and NiFeCoCr) and high-entropy (NiFeCoCrPd and NiFeCoCrMn) Cantor-Wu alloys. The bulk spin momentum densities determined by magnetic Compton scattering are remarkably isotropic, and this is a consequence of the smearing of the electronic structure by disorder scattering of the electron quasiparticles. Nonzero x-ray magnetic circular dichroism signals are observed for every element in every alloy indicating differences in the populations of the majority and minority spin states implying finite magnetic moments. When Cr is included in the solid solution, the Cr spin moment is unambiguously antiparallel to the total magnetic moment, while a vanishingly small magnetic moment is observed for Mn, despite calculations indicating a large moment. Some significant discrepancies are observed between the experimental bulk and surface magnetic moments. Despite the lack of quantitative agreement, the element-specific surface magnetic moments seem to be qualitatively reasonable.