The collision of low-flux vapor-generated Mg atoms with a methoxy-terminated self-assembled monolayer (SAM) at room temperature results primarily in nonreactive scattering from the surface. Those atoms that adsorb undergo reaction via O-C bond insertion to form Mg-O-R products, with an estimated activation energy of 38 ± 9 kJ mol-1. These products, in turn, provide nucleation sites for the subsequent formation of Mg clusters. As growth continues, a nonuniform Mg overlayer eventually forms. These behaviors contrast with that of vapor-deposited Al (which shows a high sticking probability and low chemical reactivity under the same experimental conditions). This behavior is consistent with quantum chemical predictions of differences in the ability of the -OCH3 group to stabilize these metal atoms. Overall, these results highlight the importance of dynamic processes in controlling the interfacial chemistry and metal overlayer morphology in vapordeposited films on organic surfaces.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films