Nanowire formation in self-assembled monolayers from fluorocarbon-hydrocarbon on Au(111)

We have studied phase-separation and patterning of self-assembled monolayers (SAMs) on Au(111). In this study, we used an ethanol solution of mixed unsymmetric disulfide with hydrocarbon and fluorocarbon chains [CF(3)(CF(2))(5)(CH(2))(2)S-S(CH(2))(7)CH(3)], and a symmetric disulfide of hydrocarbon chains [CH(3)(CH(2))(7)S-S(CH(2))(7)CH(3)], to derive the SAMs. Then we obtained a wire-like structure with a width of 5 nm extending to about 100 nm in these SAMs after they were annealed at 100 degrees C for 8 h. The formation of nanowires indicated that anisotropic nucleation of hydrocarbon parts along the [<(11)over bar>2] direction of the Au surface occurred. (C) 1998 Elsevier Science B.V. All rights reserved.