Step roughness on vicinal Ag(111)

Time dependence of step fluctuations on vicinal Cu(1 1 19) surfaces investigated by tunneling microscopy

“…Fluctuations in the position of steps on a coarser scale have also been observed on silicon surfaces at high temperatures [6]. In this Letter we report on a quantita- causes the "frizzy" [2] appearance of the steps at higher temperature [ Fig Rather than by counting the individual kinks in such images one may determine their concentration using the step correlation function F(y) defined as [3]. b is equal to the kink concentration Pi"if kinks of unit 1ength prevail, from which the energy for the creation of a kink Ei, is determined using [1]:…”

“…At finite temperature, steps fluctuate in time by mass transport along the step edges as well as by mass exchange with the terraces and neighboring steps. Strong fluctuations in time have been observed even at room temperature for copper and silver surfaces [1,2]. As a consequence the position of a step on the surface can move in the time interval between two scan lines which gives rise to a "frizzy" appearance of steps.…”

Attractive interaction between steps

“…Evidence for a repulsive interaction was also obtained recently for silicon surfaces vicinal to (111) by observing the terrace-width distribution directly in tunneling microscopy [10]. [12). Consequently, the step-step distance distribution measured on a flat (100) surface is not peaked at the possible atomic distances, but is rather a continuous Gaussian distribution.…”

“…The frizzed appearance of steps disappears at low temperatures [12]. A quantitative study of the frizziness together with a theoretical modeling was also performed and will be published elsewhere [13].…”

STM-induced formation of Ag islands on Ag(111)

“…This can account for the slightly round shapes of several step edges at higher resolution in 3a,b. The fuzziness of the Ag step edges, which has been reported in the literature [10,11], has not been observed because of the lower resolution in the vibration mode. An improvement in the resolution could be reached by first modifying the surface in the vibrating STM mode, followed by imaging under the usual conditions.…”