STM observations of a self-assembled structure of stearic acid Langmuir-Blodgett films with molecular resolution

Abstract

Silver ions confined in the silver stearate Langmuir-Blodgett (LB) films of 8-14 layers were electrochemically reduced, which enabled the observation of well-ordered scanning tunneling microscopy images of the films with molecular resolution. A hexagonal packing of the hydrophobic chains was obtained, which was superimposed on the two-dimensional Ag clusters of 2-3 nm diameter. Furthermore, a (2x1) structure of the hexagonal packing was observed. It was attributed to a self-assembled structure of the hydrophilic surface of the LB films through hydrogen bonding.