Figure 4: In situ TEM observation of bootstrapping filament growth and void formation.
From: Electrochemical dynamics of nanoscale metallic inclusions in dielectrics
(a) Schematic of the experimental setup. (b–e) Real-time TEM images showing continuous filament growth within a 40-nm-thick SiO2 film (applied voltage: 8 V). Scale bar, 20 nm. (f–j) Schematic illustration of the bootstrapping filament growth mode. (f) Ag ionization at the active electrode. (g) The nucleation of Ag nanoclusters near the active electrode. These nanoclusters act as bipolar electrodes in subsequent filament growth. (h) The growth of Ag nanoclusters at new positions that are closer to the inert electrode. (i) Migration of Ag nanoclusters leads to void formation marked by the dashed line. (j) Continued filament growth via step-by-step void refilling from the active electrode.
