Annealed decanethiol monolayers on Au(111) - intermediate phases between structures with high and low molecular surface density

Self-assembled monolayers of decanethiol on Au(111) have been investigated using high resolution scanning tunneling microscopy (STM). After the anneal ing of the as-adsorbed densely packed c(2 root 3 x 4 root 3)R30 degrees str ucture and before the formation of a previously described low density (11.5 x root 3) stripe phase three different phases with intermediate molecular surface density have been observed. We present highly resolved and distorti on-corrected STM images for both the (7.5 x root 3) stripe phase and the me shlike structure. We describe a mixed (7.5/11.5 x root 3) stripe phase that shows a switching of the stripe arrangement. (C) 2000 Elsevier Science B.V . All rights reserved.