Low dimensional structure formation in self-assembled monolayers on Au(111)

We have studied the phase-separation of self-assembled monolayers (SAMs) of dialkyl disulfides on Au surface. Initially, the heat-induced phase-separa tion of SAMs consisting of unsymmetric disulfide molecules (CF3(CF2)(5)(CH2 )(2)S-S(CH2)(7)CH3) of hydrocarbon and fluorocarbon chains was investigated . We proved that the dimer structure cleaved on the Au surface. Subsequentl y, we formed one-dimensional nanostructures utilizing an anisotropic phase- separation of SAMs consisting of a mixture of the above unsymmetric disulfi de and a symmetric disulfide of hydrocarbon (CH3(CH2)(7)S-S(CH2)(7)CH3). Th e wire-like structure with a width of 5 nm and a length approximate to 100 nm was observed by scanning tunneling microscopy. (C) 1999 Elsevier Science B.V. All rights reserved.