Cohesion properties of incoherent Fe/W interfaces: A DFT study

Abstract A systematic study based on density functional theory (DFT) simulation on the cohesion properties of incoherent Fe/W interfaces, Fe(100)/W(100), Fe(110)/W(110) and Fe(100)/W(110) interfaces, is presented. Results show that Fe(100)/W(110) interface is the most stable with the lowest interface energy, while Fe(110)/W(110) interface has the highest strength. In all three Fe/W interfaces, the disorder of lattice can be found mainly in Fe lattice. In Fe(100)/W(100) interface, a pseudomorphic structure is formed at the 1st Fe layer close to W layer. The formation energy of monovacancy in Fe/W interfaces is lower than it in bulk Fe or W, suggesting the formation of vacancy is easy at these Fe/W interfaces region. Moreover, Fe(100)/W(110) interface shows a significant sink effect to both H and He. Furthermore, the density of states and the charge transfer of Fe/W interfaces are investigated to give a deep understanding of cohesion properties.