Growth mechanism of long chain compounds on the surface of amorphous carbon film with normal molecular orientation

Abstract

A long chain compound, calcium stearate ((CH 3(CH 2) 16CO 2) 2Ca), was vacuum-deposited onto an amorphous carbon film kept at 0°C to form plate-like crystals, in which molecules arranged normal to the surface. After deposition, the small crystals on the substrate were annealed at 25–80°C for 5–60 min. They coalesced with each other and grew larger with increasing the temperature of the substrate and the elapsing period. The size of the crystals and the number of them in unit area were estimated by using transmission electron micrographs to confirm the mechanism of crystal growth and surface migration of long chain molecules.