LOW-TEMPERATURE RECONSTRUCTION PATHWAY TO THE SI(111)(ROOT-3X-ROOT-3)R30-DEGREES-AG INTERFACE

Using the spectroscopic capabilities of a scanning tunneling microscop e, we identified and investigated a low-temperature reconstruction pat hway for forming Si(111)(root 3 x root 3)R30 degrees-Ag from the Si(11 1)3 x 1-Ag interface. A metastable intermediate phase consisting of on e-dimensional atom chains atop the Si(111)3 x 1-Ag reconstruction stab ilizes locally. The density of states at the chains indicates a Ag-Si bonding configuration similar to that of the (root 3 x root 3)R30 degr ees reconstruction. We propose a mechanism for the (3 x 1) to (root 3 x root 3)R30 degrees phase transformation at low temperature.