Interplay between magnetism and short-range order in medium- and high-entropy alloys: CrCoNi, CrFeCoNi, and CrMnFeCoNi
Interplay between magnetism and short-range order in medium- and high-entropy alloys: CrCoNi, CrFeCoNi, and CrMnFeCoNi
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DOI：
10.1103/physrevmaterials.7.053801
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发表时间：
2023-03
影响因子：
3.4
通讯作者：
Christopher D. Woodgate;D. Hedlund;L. H. Lewis;J. Staunton
中科院分区：
文献类型：
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作者：
Christopher D. Woodgate;D. Hedlund;L. H. Lewis;J. Staunton
磁性对预测的原子短程有序在三个中等和高熵合金的影响进行了研究，使用第一性原理，全电子，朗道型线性响应理论，再加上基于晶格的原子模型。我们进行两组线性响应计算：一个在其中的顺磁状态建模内的无序的局部矩图片，和一个在其中的系统建模在磁有序的状态，这是亚铁磁性的合金在这项工作中考虑。我们表明，磁性的治疗可以有显着的影响，预测的原子有序的温度，也是原子秩序本身的性质。在CrCoNi，我们发现，原子顺序的性质的变化是从$\mathrm{L}1_2$-样时，在顺磁状态建模MoPt$_2$-样时，假设系统具有磁有序建模。在CrFeCoNi中，当我们将系统从磁无序转变为磁有序时，Fe和其他元素之间的原子相关性急剧增强。我们的研究结果表明，它是必要的，以考虑磁状态时，建模多组分合金中含有中期至后期-$3D$元素。此外，我们建议，可能有高熵合金组合物包含$3D$过渡金属，将表现出特定的原子短程有序时，在施加的磁场热处理。这有可能提供一个路线，调整这类材料的物理和机械性能。
The impact of magnetism on predicted atomic short-range order in three medium- and high-entropy alloys is studied using a first-principles, all-electron, Landau-type linear response theory, coupled with lattice-based atomistic modelling. We perform two sets of linear-response calculations: one in which the paramagnetic state is modelled within the disordered local moment picture, and one in which systems are modelled in a magnetically ordered state, which is ferrimagnetic for the alloys considered in this work. We show that the treatment of magnetism can have significant impact both on the predicted temperature of atomic ordering and also the nature of atomic order itself. In CrCoNi, we find that the nature of atomic order changes from being $\mathrm{L}1_2$-like when modelled in the paramagnetic state to MoPt$_2$-like when modelled assuming the system has magnetically ordered. In CrFeCoNi, atomic correlations between Fe and the other elements present are dramatically strengthened when we switch from treating the system as magnetically disordered to magnetically ordered. Our results show it is necessary to consider the magnetic state when modelling multicomponent alloys containing mid- to late-$3d$ elements. Further, we suggest that there may be high-entropy alloy compositions containing $3d$ transition metals that will exhibit specific atomic short-range order when thermally treated in an applied magnetic field. This has the potential to provide a route for tuning physical and mechanical properties in this class of materials.