High entropy alloys (HEAs) have shown good mechanical, electrical, and magnetic properties; thus, they are considered as next-generation structural–functional integration materials. Recent investigations have reported that the “negative mixing enthalpy solid solution” strategy can improve strength–ductility synergy in HEAs {An et al., Nature, 2024, 625(7996)}. However, its effects on magnetic properties remain unknown. Here, CoCrFeNiMn₁₀Si₁₀ HEA (Si10) with high negative mixing enthalpy was fabricated via gas atomization. In this study, the effects of Si substitution and rapid solidification on the magnetic properties of alloy were mainly investigated. Results indicated that most as-atomized Si10 particles exhibited a fine dendritic face-centered cubic phase, whereas a minor body-centered cubic (BCC) phase and a Cr₃Ni₅Si₂-type phase were found in ultrafine particles (less than 5 μm in diameter). Si substitution changed the magnetic transformation from Néel transformation (~50 K) in CoCrFeMnNi (Cantor) alloy to Curie transformation (~70 K) in Si10 alloy. The magnetization of the as-atomized Si10 powder was higher than that of the Cantor alloy and the as-homogenized Si10 powder, particularly at a temperature ranging from Curie temperature to ~800 K. The high magnetization of the as-atomized Si10 powder was primarily due to the presence of a metastable BCC phase and Cr₃Ni₅Si₂-type phase. Moreover, a modified model was proposed to explain the magnetism of multicomponent alloys based on Slater’s equation, which is in accordance with the reported experimental studies.

中文翻译：

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快速凝固 Si 取代的 CoCrFeMnNi 高熵合金的相演变和磁性能


高熵合金 （HEA） 具有良好的机械、电气和磁性;因此，它们被认为是下一代结构-功能集成材料。最近的研究报告称，“负混合焓固溶体”策略可以提高 HEA 的强度-延展性协同作用 {An et al.， Nature， 2024， 625（7996）}。然而，它对磁性能的影响仍然未知。在这里，通过气体原子化制备了具有高负混合焓的 CoCrFeNiMn₁₀Si₁₀ HEA （Si10）。本研究主要研究了 Si 取代和快速凝固对合金磁性能的影响。结果表明，大多数原子化的 Si10 颗粒表现出细的树枝状面心立方相，而在超细颗粒（直径小于 5 μm）中发现了少量的体心立方 （BCC） 相和 Cr₃Ni₅Si₂ 型相。Si 取代将磁相变从 CoCrFeMnNi （Cantor） 合金中的 Néel 相变 （~50K） 变为 Si10 合金中的居里相变 （~70K）。雾化态 Si10 粉末的磁化强度高于 Cantor 合金和均质化 Si10 粉末，尤其是在居里温度至 ~800K 的温度范围内。原子化 Si10 粉末的高磁化强度主要是由于亚稳态 BCC 相和 Cr₃Ni₅Si₂ 型相的存在。此外，还提出了一个基于 Slater 方程的改进模型来解释多组分合金的磁性，这与报道的实验研究一致。