Relaxation dynamics of labyrinthine submonolayer films

摘要

To explore the relaxation process of percolating labyrinthine submonolayer films, we observe in real-time the evolution of a submonolayer film with a coverage of-0.7 monolayer on SrTiO_3(001) at 670 ℃ using scanning tunneling microscopy. We find that the characteristic length begins to increase after an incubation time. During the incubation time, percolating grooves are segmented by local pinch-off events predominantly driven by thermal fluctuations. The occurrence frequency of the pinch-off events markedly decreases with an increase in the characteristic length. In the second stage, reshaping of the disconnected irregular vacancy islands occurs by edge diffusion. Finally, small vacancy islands disappear via Ostwald ripening by terrace diffusion.