Fig. 1. HAADF-STEM images of two congruent GB phase transitions.
a, Overview image of the transition at a near symmetric Σ 19b [11-1] GB with (178) boundary plane. The domino and pearl structures (or GB phases) are highlighted in red and blue, respectively. The overall misorientation of the GB is ~48º with a deviation in inclination from the symmetric orientation of ~1º. b, Magnified view of the GB transition on the right highlighting the differences in structural units of both boundary segments. c, GB phase transition at a vicinal Σ19b [11-1] GB with ~47º misorientation and boundary planes of (011) lower grain and (279) upper grain. (d) and e illustrate close-up images of the domino and pearl structure of the vicinal boundary, respectively. The scale bar is 1 nm in all images.
