Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
Graduate Group in Applied Science & Technology, University of California, Berkeley, CA 94720.
Proc Natl Acad Sci U S A. 2021 Mar 30;118(13). doi: 10.1073/pnas.2020540118.
The presence, nature, and impact of chemical short-range order in the multi-principal element alloy CrCoNi are all topics of current interest and debate. First-principles calculations reveal that its origins are fundamentally magnetic, involving repulsion between like-spin Co-Cr and Cr-Cr pairs that is complemented by the formation of a magnetically aligned sublattice of second-nearest-neighbor Cr atoms. Ordering models following these principles are found to predict otherwise anomalous experimental measurements concerning both magnetization and atomic volumes across a range of compositions. In addition to demonstrating the impact of magnetic interactions and resulting chemical rearrangement, the possible explanation of experiments would imply that short-range order of this type is far more prevalent than previously realized.
多主元合金 CrCoNi 中化学短程有序的存在、本质及其影响都是当前关注和争论的话题。第一性原理计算表明，其起源本质上是磁性的，涉及相似自旋 Co-Cr 和 Cr-Cr 对之间的排斥，而这种排斥作用由第二近邻 Cr 原子磁有序亚晶格的形成来补充。根据这些原理得出的有序模型被发现可以预测在一系列成分下有关磁化和原子体积的反常实验测量。除了证明磁性相互作用和由此产生的化学重排的影响外，对实验的可能解释意味着这种类型的短程有序比以前认识到的要普遍得多。
