Fig. 9: Schematic representation of nanolite growth mechanisms.

Small (<50 nm), subspherical-spherical nanolites, such as those observed in the STEM images, may form through a classical nucleation and growth mechanism. With increasing time, nanolites may aggregate to form larger, more irregular shaped structures such as those observed in the ptychographic images. The textures observed in the samples show less evidence of Ostwald ripening. Instead, Ostwald ripening may lead to the formation of microlites. Inset a shows a HAADF-STEM image (Fig. 3d) of spherical-subspherical nanolites (scale bar = 25 nm), whilst inset b shows a SEM image (Fig. 2b) of larger aggregates (scale bar = 2 μm).