In this paper we report a new fundamental understanding of chemically-biased diffusion in Ni–Fe random alloys that is tuned/controlled by the intrinsic quantifiable chemical complexity. Development of radiation-tolerant alloys has been a long-standing challenge. Here we show how intrinsic chemical complexity can be utilized to guide the atomic diffusion and suppress radiation damage. The influence of chemical complexity is shown by the example of interstitial atom (IA) diffusion that is the most important defect in radiation effects. We use μs-scale molecular dynamics to reveal sluggish diffusion and percolation of IAs in concentrated Ni–Fe alloys. We develop a mean field diffusion model to take into account the effect of migrating defect energy properties on diffusion percolation, which is verified by a new kinetic Monte Carlo approach addressing detailed processes. We demonstrate that the local variations in the ground state energy of IA configurations in alloys, reflecting the chemical difference between alloying components, drives the percolation effects for atomic diffusion. Percolation, chemically-biased and sluggish diffusion are phenomena that are directly related to the chemical complexity intrinsically to multicomponent alloys.

在本文中，我们报告了对Ni-Fe无规合金中化学偏向扩散的新的基本理解，该现象由固有的可量化化学复杂性来调节/控制。耐辐射合金的开发一直是一个长期的挑战。在这里，我们展示了如何利用固有的化学复杂性来指导原子扩散并抑制辐射损伤。间隙原子（IA）扩散的例子表明了化学复杂性的影响，间隙原子是辐射效应中最重要的缺陷。我们使用μs尺度的分子动力学来揭示IAs在浓镍铁合金中的缓慢扩散和渗流。我们开发了一个平均场扩散模型，以考虑缺陷能量特性的迁移对扩散渗流的影响，新的动力学蒙特卡洛方法论证了详细的过程，这一点得到了验证。我们证明合金中IA构型的基态能量的局部变化反映了合金成分之间的化学差异，驱动了原子扩散的渗滤效应。渗流，化学偏向和缓慢扩散是与多组分合金固有的化学复杂性直接相关的现象。