Adsorption and thermal treatments of 1-dodecene on Si(100) investigated by STM

We investigate the atomic behaviour of long-chain 1-dodecene adsorbed on Si(100) using a scanning tunnelling microscope with an exposure of 30 to 2.4 Langmuirs. Unlike previous reports on short-chain molecules, remarkable self-ordered assembly of molecules is not observed at room temperature, which is possibly attributed to the asymmetric molecular structure with long chains of 1-dodecene. After annealing at 500-580 °C, ordered patterns form with a c(4 × 4) structure, accompanied with thermal decomposition of molecules.