Abstract AlxFeNiCrCo ( 0 ≤ x ≤ 1.5 ) high entropy alloys (HEA) have been studied both experimentally and theoretically, considering the multi-phase character of investigated samples. Magnetic properties of these alloys (ordering temperatures and average magnetic moments) were determined from magnetization measurements (VSM), being found strongly dependent on Al content. Decomposition of this HEA system into phases with different stoichiometries and different crystal structures was analyzed using electronic structure calculations by the KKR and KKR-CPA methods, and discussed in terms of total energy balance. Additional energy lowering was achieved by admitting atoms separation in Al- and Ni-rich bcc-phase within B2-like crystal structure, and in consequence ordering of some elements constituting HEA, has been determined. Accounting for all experimentally detected phases in AlxFeCrNiCo samples, it was found that calculated total and site-decomposed magnetic moments strongly depended on stoichiometries, more particularly on crystal structures. Comparison of KKR calculations based on ordered supercell models and KKR-CPA results performed for fully disordered model of HEA systems, clearly indicates strong influence of local atoms neighborhood on magnetic moments. It is observed that in spite of increase of nominal Al content in AlxFeNiCrCo HEA, the actual concentration of Al in the detected f c c and b c c phases only slightly changes. Hence the strong measured variation of saturated magnetization with x is essentially driven by relative phase contributions. On the whole, much better agreement between measured and theoretical magnetic moments was obtained when averaging computational results obtained for experimentally detected phases and their contributions, than KKR-CPA results achieved for single-phase HEAs with nominal compositions.

中文翻译：

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bcc/fcc相偏好对Al CrFeCoNi高熵合金磁性能的影响

摘要 AlxFeNiCrCo ( 0 ≤ x ≤ 1.5 ) 高熵合金 (HEA) 已从实验和理论两方面进行了研究，同时考虑到了所研究样品的多相特性。这些合金的磁性能（排序温度和平均磁矩）由磁化测量 (VSM) 确定，发现强烈依赖于 Al 含量。使用 KKR 和 KKR-CPA 方法的电子结构计算分析了该 HEA 系统分解成具有不同化学计量和不同晶体结构的相，并根据总能量平衡进行了讨论。通过在 B2 类晶体结构内允许富铝和富镍 bcc 相中的原子分离来实现额外的能量降低，因此已确定构成 HEA 的某些元素的排序。考虑到 AlxFeCrNiCo 样品中所有实验检测到的相，发现计算的总磁矩和位点分解磁矩强烈依赖于化学计量，尤其是晶体结构。基于有序超胞模型的 KKR 计算与 HEA 系统完全无序模型的 KKR-CPA 结果的比较清楚地表明局部原子邻域对磁矩的强烈影响。据观察，尽管 AlxFeNiCrCo HEA 中的标称 Al 含量增加，但检测到的 fcc 和 bcc 相中的实际 Al 浓度仅略有变化。因此，饱和磁化强度随 x 的强烈测量变化基本上是由相对相位贡献驱动的。总体上，