Multifrequency atomic force microscopy: compositional imaging with electrostatic force measurements.

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Atomic force microscopy (AFM) is a powerful tool for surface analysis.
• Expanding AFM capabilities for detailed compositional imaging is crucial for understanding heterogeneous materials.

Purpose of the Study:

• To demonstrate how single-pass Kelvin force microscopy (KFM) and dC/dz measurements enhance compositional imaging.
• To validate these techniques across a wide range of materials and environments.

Main Methods:

• Utilized intermittent contact mode AFM with force gradient detection.
• Performed Kelvin force microscopy (KFM) and capacitance gradient (dC/dz) measurements.
• Conducted studies in various environments, including different humidity levels and organic solvent vapors.

Main Results:

• Achieved nanometer-scale spatial resolution for surface potential and capacitance gradient mapping.
• Verified the effectiveness of KFM and dC/dz on metal alloys, polymers, organic layers, and liquid-like objects.
• Demonstrated that surface potential and dC/dz variations complement each other for identifying components in heterogeneous materials.
• Showcased in situ imaging in different environments to facilitate constituent recognition in multicomponent polymers via selective swelling.

Conclusions:

• Single-pass KFM and dC/dz measurements significantly expand the compositional imaging capabilities of AFM.
• These techniques provide sensitive and high-resolution characterization of surface properties.
• Environmental control during imaging enhances the ability to differentiate components in complex materials.