.

Fig. 4.. (a) The atomic-scale HAADF-STEM image of a semicoherent interface on the edge of a θ' precipitate viewed along [100]_α and (b) the crucial diffusion region obtained from the selected area in (a). Additional Al atoms and interstitial Cu atoms were marked by green arrows and orange circles, respectively. Simulated images for θ'_P1 and θ' cell are overlaid in the image. (c) Intensity profiles of A and B planes marked in (a). The blue and red profiles represent the column intensity variations on A and B planes, respectively. The fluctuation of intensity reflects the atomic diffusion.