The physical and mechanical properties can be greatly affected by lattice distortion caused by interstitial atoms. However, at nanoscale, effect of interstitial atom on high entropy alloys (HEAs) still requires to be discussed. Here, we study effect of interstitial N atom on formation energy, lattice constant, elastic modulus, density of states, and deformation charge density in FeCoCrNiMn HEAs using first-principles calculation. The results show that the incorporation of N atom makes HEA more difficult to stabilize due to high formation energy. The ductility of N-doped FeCoCrNiMn HEA increases, while its elastic modulus is reduced. In addition, the doped N atom can lead to the strong anisotropy in N-doped HEA. The N-doped octahedral interstice results in an obvious change of elastic modulus and ductility, and the N-doped tetrahedral interstice makes HEA isotropic. The current work reveals a fundamental role in interstitial atom and a paradigm for creating new and superior HEAs.

间隙原子引起的晶格畸变会极大地影响物理和机械性能。然而，在纳米尺度上，仍然需要讨论间隙原子对高熵合金（HEA）的影响。在这里，我们使用第一性原理计算研究间隙N原子对FeCoCrNiMn HEA中形成能，晶格常数，弹性模量，状态密度和形变电荷密度的影响。结果表明，由于高形成能，N原子的结合使HEA更难以稳定。N掺杂的FeCoCrNiMn HEA的延展性增加，而其弹性模量降低。另外，掺杂的N原子可导致掺杂N的HEA中的强各向异性。N掺杂的八面体间隙会导致弹性模量和延展性发生明显变化，N掺杂的四面体间隙使HEA各向同性。当前的工作揭示了在间隙原子中的基本作用以及创建新的高级HEA的范例。