A hybrid first-principles/Monte Carlo simulation is combined with experiments to study the structure and elastic properties of CoCrNi_x (x = 1–0.5) alloys. The experimental X-ray diffraction patterns show that the structures have changed from the single-phase face-centered cubic (FCC) structure at x = 1–0.8 to the coexistence of FCC and the hexagonal close-packed structures at x = 0.7–0.5, which is further confirmed by calculations on mixing energies. The elastic moduli by calculation are basically in agreement with experiments. Room-temperature tension shows that the six alloys have a certain plasticity, the strength and plasticity of the alloys have a linear decrease with the decrease in Ni contents, and the plasticity of the alloys drops from 84 to 23%. Furthermore, first-principles density function theory calculations were employed to reveal the electronic and magnetic structures of alloys. The electron density of states for all alloys is asymmetrical, which illustrates that the alloys are ferromagnetism. It is found that Cr atoms can suppress the ferromagnetism of alloys, since Cr atoms have both positive and negative magnetic moments in all alloys.

中文翻译：

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CoCrNi x中熵合金中FCC到HCP的相变

混合第一性原理/蒙特卡罗模拟与实验相结合，以研究CoCrNi _x（x  = 1-0.5）合金的结构和弹性性能。实验X射线衍射图表明，该结构已经从单相的面心立方（FCC）结构在改变X  = 1-0.8到FCC的共存，并在密排六方结构X = 0.7-0.5，这可以通过混合能的计算进一步确认。计算得出的弹性模量与实验基本吻合。室温张力表明这六种合金具有一定的可塑性，随着镍含量的降低，其强度和可塑性呈线性下降，合金的可塑性从84％下降至23％。此外，第一原理密度函数理论计算被用来揭示合金的电子和磁性结构。所有合金的状态电子密度都是不对称的，这说明合金是铁磁性的。发现Cr原子可以抑制合金的铁磁性，因为Cr原子在所有合金中都具有正和负磁矩。