Fig. 2

Growth of dendritic nanostructures in pre-exposed area. LCTEM image series acquired with \(\dot{d}\) = 155 electrons/Ųs. After irradiating a large area for 45 s (total dose at t = 0 s is 6975 electron/Ų), TEM imaging was magnified to follow the growth of sharp dendrites on nearly spherical NPs. The filling degree of the whole NP is reduced from 79 % at t = 0 s to 43 % at t = 55 s (see Fig. 1e). Acquisition time is indicated over each image