The single-phase equiatomic CoCrFeMnNi alloy is a random solid solution of five elements on the face-centered cubic lattice, whose pure constituents crystallize in very different structures and exhibit diverse magnetic properties. Due to the randomness of the alloy, 80% of nearest neighbor bonds are between unlike elements and thus the details of bonding in pure structures are less important. The elastic moduli of this alloy give rise to small Cauchy pressure C12-C44, which suggests that the dominant part of bonding may be described by a simple pair potential. We test this hypothesis by developing a long-range Lennard-Jones potential in which the equilibrium crystal structures of pure constituents are taken as reference. The standard mixing rules for regular solutions are then adopted to obtain parameters for bonds between unlike elements in the quinary system. The transferability of this potential to quaternary CoCrFeNi, ternary CoCrNi, and binary FeNi alloys is investigated and the predictions are compared with experiments and DFT calculations. By sampling over a large number of random configurations, we investigate the effect of compositional randomness on misfit volumes, energies of point defects and stacking faults, and the dislocation friction stresses experienced by moving edge and screw dislocations.

中文翻译：

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随机 fcc CoCrFeMnNi 合金的有效对势

单相等原子 CoCrFeMnNi 合金是五种元素在面心立方晶格上的随机固溶体，其纯成分以非常不同的结构结晶并表现出不同的磁性能。由于合金的随机性，80% 的最近邻键位于不同元素之间，因此纯结构中的键合细节不太重要。这种合金的弹性模量产生小的柯西压力 C12-C44，这表明键合的主要部分可以用简单的对势来描述。我们通过开发一个长程 Lennard-Jones 势来检验这个假设，其中纯成分的平衡晶体结构被作为参考。然后采用常规溶液的标准混合规则来获得五元系统中不同元素之间键的参数。研究了这种电位向四元 CoCrFeNi、三元 CoCrNi 和二元 FeNi 合金的可转移性，并将预测与实验和 DFT 计算进行了比较。通过对大量随机配置进行采样，我们研究了成分随机性对失配体积、点缺陷和堆垛层错的能量以及移动边缘和螺旋位错所经历的位错摩擦应力的影响。