Conformation and motion of monolayer lubricant molecule on magnetic disks

The conformation and diffusive motion of molecules of monolayer perfluoropolyether lubricants on magnetic disks have been clarified by investigating surface energy and spreading characteristics. A mobile molecule lies flat on the disk surface and a bonded molecule lies less flat than a mobile one. In addition, a model for the diffusive motion of the mobile molecule is presented. The diffusive motion can be explained by a modified reptation theory. The mobile molecule makes a snake-like diffusive motion through the bonded ones. These results are useful for building a tribological model of a monolayer lubricant on a magnetic disk.