A rate theory study of helium bubble formation and retention in Cu–Nb nanocomposites

Ab initio simulations of the structure, energetics and mobility of radiation-induced point defects in bcc Nb

“…Continuing with Table 1, in a very recent article Dunn et al [5] found a formation energy value of 3.26 eV for the most stable SIA, without explicitly mentioning its type. This result differs from our values as well as from all the other previous ones.…”

“…Concerning the presence of He impurity atoms in metallic Nb, there have been in the past several works dealing with the energetics and stability in the bulk crystal [5,11,35]. The main motivation of these studies was to analyse the clustering and mobility processes in the metallic matrix, eventually leading to the creation of He bubbles and voids that are detrimental to the performance of the material [36].…”

“…However, no computed migration data were actually given, and it was only after the work of Kashinath and Demkowicz [11] that a working predictive interatomic NbeHe potential based on DFT simulations appeared in the literature. This potential was subsequently used by Dunn et al [5] to derive formation, binding and migration energetics of the NbeHe system via cMD codes, as the first steps in an effort to unravel the mechanisms of helium trapping and solubility on the interfaces of CueNb nano-laminates.…”

Point defect stability in a semicoherent metallic interface

“…DFT techniques are the first crucial step to create an energy and force database that provides a solid foundation for subsequent Molecular Dynamics (MD) and kinetic Monte Carlo (kMC) simulations lying at an upper level of what has become commonly known as a multiscale modeling approach 7 . Following this idea, a new DFT-based embedded atom method (EAM) interatomic Cu-Nb-He potential has been developed 8 and subsequently used in MD simulations to obtain formation, binding and migration energies of helium clusters in Cu-Nb that in turn are input for kMC codes 9 . Subsequently, stable and efficient storage of He bubbles at interfaces has been theoretically proposed in the Cu/Nb system 10 .…”

Role of interfaces on the trapping of He in 2D and 3D Cu–Nb nanocomposites

“…Owing to their complexity, however, they are not suitable for elucidating the relationship between interface structure and He trapping. Interphase boundaries between immiscible metals with semi-coherent interfaces, such as in Cu-Nb [17,18], Cu-V [19,20], Cu-Fe [21], and Ag-V [22], are more appropriate for this latter purpose as they are good defect sinks, are stable under irradiation, and their interface structures can be controllably varied, characterized, and modelled [6,[23][24][25]. Previous research on Cu-Nb and Cu-V produced by physical vapor deposition (PVD) has indeed shown that the Kurdjumov-Sachs (KS) orientation relationship with a dominant (111)FCC||(110)BCC interface habit plane, often referred to as (111)KS, effectively suppresses He-filled bubble formation.…”