Helium bubble precipitation at dislocation networks

We report on a study of nanoscale He bubble precipitation and growth at a twist grain boundary in two face-centered cubic materials. Experimentally, the twist boundary in Au captures all the He in the sample, forming equal-sized bubbles at the dislocation intersection junctions. Simulations in Cu reveal a complex structure of the interface and different He pressure in the interface bubbles compared to bulk, providing an explanation for the high efficiency of the boundary to capture all the He in the sample.