Mechanical and Electrical Properties of Alkanethiol Self-Assembled Monolayers: A Conducting-Probe Atomic Force Microscopy Study
Frank W. DelRio, Robert F. Cook
The structure-property relationships for methyl-terminated alkanethiol (CH3(CH2)n1SH, where n is the number of carbons in the molecular chain) self-assembled monolayers on gold substrates are considered, with a particular emphasis on using conducting-probe atomic force microscopy (CPAFM) to assess the mechanical and electrical properties and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy to determine the molecular structure. CPAFM measurements are analyzed with an elastic adhesive contact model, modified by a first-order elastic perturbation method to account for substrate effects, and a parabolic tunneling model, appropriate for a metal-insulator-metal contact in which the insulator is extremely thin. NEXAFS carbon K-edge spectra are used to compute the dichroic ratio for each film, which provides a quantitative measure of the molecular structure. The combination of the two measurement methods provides clear property trends for this system over a wide range of n and a general methodology for the optimization of self-assembled monolayers for micro- and nano-electromechanical systems, magnetic storage devices, and other applications.
Scanning Probe Microscopy in Nanoscience and Nanotechnology, volume 2
and Cook, R.
Mechanical and Electrical Properties of Alkanethiol Self-Assembled Monolayers: A Conducting-Probe Atomic Force Microscopy Study, Scanning Probe Microscopy in Nanoscience and Nanotechnology, volume 2, Springer-Verlag, Heidelberg, -1, [online], https://doi.org/10.1007/978-3-642-10497-8
(Accessed February 26, 2024)