Atom probe microscopy of self-assembled monolayers: preliminary results

Area of Science:

• Materials Science
• Surface Science
• Analytical Chemistry

Background:

• Self-assembled monolayers (SAMs) are crucial in modifying surface properties.
• Understanding the interface between organic molecules and metal substrates is vital for advanced applications.
• Atom probe tomography (APT) offers high-resolution 3D chemical analysis.

Purpose of the Study:

• To demonstrate the capability of APT for 3D imaging of decanethiol SAMs on metal surfaces.
• To present preliminary results on Nickel [001] and Gold [111] substrates.
• To explore the bonding mechanisms of thiols on metal surfaces.

Main Methods:

• Specimen preparation techniques for APT analysis of SAMs.
• Data-treatment methodologies for APT data.
• APT analysis of decanethiol SAMs on Ni [001] and Au [111].

Main Results:

• Successful three-dimensional imaging of decanethiol SAMs was achieved.
• Mass spectra analysis revealed no sulfur-hydrogen combinations at the metal-organic interface.
• Preliminary data presented for Ni [001] and Au [111] surfaces.

Conclusions:

• APT is a powerful tool for analyzing the structure and chemistry of SAMs.
• The absence of S-H at the interface suggests specific bonding configurations.
• Further investigation using APT can elucidate thiol-substrate bonding in detail.