Fundamentals of Au(111) Surface Dynamics: Coarsening of 2D Au Islands
Ames Laboratory; Chemistry; Materials Science and Engineering; Physics and Astronomy
Chemistry, Materials Science and Engineering, Physics and Astronomy, Ames Laboratory
The Journal of Physical Chemistry C
Au(111) surfaces play a central role in many applications, yet studies of fundamental aspects of their dynamics are limited. Thus, using scanning tunneling microscopy (STM) at 300 K, we analyze the coarsening of first-layer 2D Au islands directly on the Au(111) substrate and also of second-layer 2D Au islands. Specifically, we monitor the decay of Au first-layer islands with areas of about 100–500 nm2 in the vicinity of larger islands or extended step edges over a period of approximately 40 h, the relevant time scale for this process. Experimentally observed behavior is captured by analytical theory for terrace-diffusion-limited decay incorporating DFT results for the Au terrace diffusion barrier and the adatom formation energy. Experimental observations of second-layer island decay are also compared with appropriate analytical theory and stochastic simulations, thereby determining the effective Ehrlich–Schwoebel barrier for Au on Au(111).
DOE Contract Number(s)
AC02-07CH11358; AC02-05CH11231; CHE-1507223
Iowa State University Digital Repository, Ames IA (United States)