Using temperature to tune film roughness: nonintuitive behavior in a simple system
Ag(100) homoepitaxy constitutes one of the simplest systems in which to study thin-film growth. Yet we find that the roughness variation with temperature is extraordinarily complex. Specifically, as the deposition temperature is reduced from 300 to 50 K, the roughness of 25 monolayer films first increases, then decreases, then increases again. A transition from mound formation to self-affine (semifractal) growth occurs at approximately 135 K. The underlying mechanisms are postulated. An atomistic model incorporating these mechanisms reproduces the experimental data quantitatively.
Stoldt
CR
Departments of Chemistry, Mathematics, and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA.
Caspersen
KJ
Bartelt
MC
Jenks
CJ
Evans
JW
Thiel
PA