The structural, stability and energetics of helium-vacancy-type (He_nV_m) clusters in Fe 6.3 at% Cr alloys are studied by means of DFT calculations, considering n (m) from 0 (0) to 6 (4). The self-trapping and accumulation of interstitial helium atoms in the vacancy-free lattice caused by strong attraction are more likely to form clusters in Fe 6.3 at% Cr alloys. The trapping capacity of vacancies strengthens with the increase of m, but attenuates gradually with the increase of n, and the addition of Cr prevents the trapping of helium atoms by multi-vacancies, effectively reducing the risk of helium atoms forming clusters. The binding energies and electronic properties confirmed from the macroscopic and microscopic levels respectively that the stability of He_n-clusters gradually decreases with the increase of n. Whether the He_nV_m complexes are easily formed are determined by the number of n and m. The higher density of the helium bubble nucleate precursor in Fe 6.3 at% Cr alloys, i.e. the small He_nV_m clusters, supply more annihilation sites for recombination of radiation-induced Frenkel pairs, resulting in better radiation swelling resistance than the bulk γ-Fe. We predict spontaneous emission of vacancies or helium atoms at smaller or larger n/m ratios. In addition, the trends of the binding energy of interstitial helium and monovacancy with helium-vacancy-type complexes are discussed in detail, which provide useful information for the explanation of complex experimental phenomena.

考虑到 n (m) 从 0 (0) 到 6 (4)，通过 DFT 计算研究了 Fe 6.3 at% Cr 合金中氦空位型 (He _n V _m ) 簇的结构、稳定性和能量学。由强引力引起的间隙氦原子在无空位晶格中的自捕获和积累更有可能在 Fe 6.3 at% Cr 合金中形成团簇。空位的俘获能力随着m的增加而增强，但随着n的增加而逐渐减弱。，而Cr的加入防止了氦原子被多空位俘获，有效降低了氦原子形成团簇的风险。结合能和电子性质分别从宏观和微观层面确认了他的稳定性_ñ -clusters逐渐的增大而减小ñ。He _n V _m络合物是否容易形成取决于n和m的数量。Fe 6.3 at% Cr 合金中氦气泡成核前体的密度更高，即小的 He _n V _m簇，为辐射诱导的弗伦克尔对的重组提供更多的湮灭位点，导致比块体γ -Fe更好的抗辐射膨胀性。我们预测空位或氦原子以更小或更大的n/m比自发发射。此外，详细讨论了间隙氦和单空位与氦空位型配合物的结合能趋势，为解释复杂的实验现象提供了有用的信息。