Extended Data Fig. 1. EBSD characterization of the Cu thin film.

The [11-1] tilt GBs have been obtained by thin film deposition of Cu on (0001) oriented Sapphire substrate. The inverse pole figure shows that all grains are in ⟨111⟩ orientation with an average grain size of ≤100 μm. The majority of GBs in the film are twin and low angle GBs (up to 70%), but crucially Σ7, Σ19b, Σ37c and corresponding asymmetric boundaries are also present. The most prominent GBs are colored. The Σ19b GBs are highlighted in red. The white rectangle in the center shows a position where a TEM specimen has been extracted.