Fig. 4: Comparison of 1D Ni concentration line profiles obtained from APT along the connecting line between the centers of the two bubbles with results from 2D IK model simulations across three ROI sizes.

a ROI diameter = 5 nm; b ROI diameter = 7 nm; c ROI diameter = 10 nm. The grey regions represent the helium bubbles. Dashed lines indicate the bubble surface.