Energetic analysis of He and monovacancies in Cu/W metallic interfaces

Abstract A systematic study based on density functional theory (DFT) simulations of the stability of one He impurity atom at two different interfaces formed between the low-solubility W and Cu metals is presented. The analysis includes the effect of a single vacancy at the interfaces and in the neighbouring layers. The results have been compared with bulk data presented in the literature and the well-known Kurdjumov–Sachs (KS) geometry of the Cu/Nb interface. Our exhaustive energetic analysis explains the great tendency of both defects (helium and vacancies) to find the interfaces as observed previously in the Cu/Nb case. The HeV complex is likely to be formed in the Cu/W interfaces analysed, specially inside the Cu vacancies. Our results show that Cu/W interfaces have the adequate properties to form alternative metallic multilayers for the first wall of the future fusion reactors.