Figure 1

STM image of the intersection of a screw dislocation with the surface. Between the two partials (marked by white arrows), the positions of the atoms do not change within half an hour; beyond the second partial (i.e., right of the right arrow), the step shows the frizziness expected for Ag(111) at this temperature (Refs. 10, 11). $U=-0.221\mathrm{V}$, $I=0.07\mathrm{nA}$, $T=330\mathrm{K}$; the inset shows the atomic resolution image of the region between the partials, $U=-0.221\mathrm{V}$, $I=0.12\mathrm{nA}$.Reuse & Permissions

Figure 2

Snapshots from a movie containing 385 images with one image recorded every $20\mathrm{s}$. $U=2.13\mathrm{V}$, $I=0.1\mathrm{nA}$, $T=320\mathrm{K}$. For a better impression of step height changes two 3D images are shown in the right part of the image.Reuse & Permissions

Figure 3

(Color online) Evolution of the helix: (a) Sketch indicating the angles and lengths measured; $h_i$ is measured at ${\varphi }_i$. (b) Angles ${\varphi }_3$ (filled diamonds) and ${\varphi }_4$ (open circles). The solid lines represent the angles between the step segments of a vacancy island on the same surface. (c–h) Symbols: experimental values, solid lines; linear fits, dashed line; power-law fit (see text). (c) Total step length $l={\Sigma }_{i=1}^5{l}_i$. (d) Length of step segments. (e) Step height in corners of the helix. Note that in (d) and (e) the time scales are different in the two graphs. The fluctuations around the mean values of the lengths are largely due to Brownian motion, which has been analyzed for this surface at even lower temperature (Ref. 11). For region I a reduced data set is shown only.Reuse & Permissions

Figure 4

3D representation of the passing of the full-height step along the reduced-step height between the emergence of partials. The arrows point to these partials: (a) From the movie shown in Fig. 2 at $5943\mathrm{s}$. (b) Snapshots from a movie containing 92 images with one image recorded every $15\mathrm{s}$. $U=2.13\mathrm{V}$, $I=0.02\mathrm{nA}$, $T=343\mathrm{K}$ and $170\mathrm{nm}\times 176\mathrm{nm}$.Reuse & Permissions