Exploring atomic-scale lateral forces in the attractive regime: a case study on graphite (0001).

Area of Science:

• Surface science
• Nanotechnology
• Tribology

Background:

• Atomic force microscopy (AFM) is crucial for nanoscale surface analysis.
• Understanding tip-sample interactions is key to friction and adhesion studies.
• Previous methods faced limitations in resolution and contact area effects.

Purpose of the Study:

• To develop and demonstrate a non-contact AFM method for mapping lateral forces.
• To quantify lateral forces with high resolution.
• To analyze lateral forces as a function of tip position and distance.

Main Methods:

• Utilized non-contact atomic force microscopy (AFM).
• Employed an atomically sharp Platinum/Iridium (Pt/Ir) probe tip.
• Conducted measurements at low temperatures in the attractive regime.

Main Results:

• Successfully mapped static lateral forces between a Pt/Ir tip and graphite surface.
• Achieved piconewton force and picometer position resolution.
• Observed a linear relationship between lateral and normal forces at small tip-sample distances.

Conclusions:

• The non-contact AFM method provides unique insights into nanoscale lateral forces.
• The findings offer a new approach to study friction at the atomic level.
• Lateral forces in the attractive regime are directly related to normal forces for specific tip-sample geometries.