Figure 4
From: Co nanoparticle hybridization with single-crystalline Bi nanowires
Annealing-time-dependent morphological evolution of Co film based on our suggested mechanism. Many vacancies in the Co film coalesce into tiny holes and the holes are again agglomerated in the early stage of annealing. Further annealing drives the holes to grow until neighboring holes encounter each other, leaving behind Co islands. Lastly, the Co islands are reshaped into near-hemispherical nanoparticles. The bottom row shows top views at the respective stages.