Silane adsorption on Pd(100) - a low-temperature RAIRS study

Silane adsorption and reaction on Pd(100) have been investigated between 23-80 K by reflection-absorption infrared spectroscopy (RAIRS). Exposure to a silane/argon mixture at a substrate temperature of 23 K results in physisorbed islands of silane with argon matrix isolated silane in subsequent layers. At a substrate temperature of 70 K the silane forms a uniform physisorbed layer on the surface which undergoes dissociative chemisorption at ~78 K. On Pd(100) a surface stabilised SiH moiety is formed; direct adsorption at 80 K leads to the formation of islands of SiH with overlayers of physisorbed molecular silane. The SiH species is stable to 200 K at which point complete dissociation occurs.