Electrostatic Force Microscopy on Oriented Graphite Surfaces: Where Insulating and Conducting Behaviors Coexist

TL;DR

This study uses electrostatic force microscopy to reveal coexistence of insulating and conducting regions on graphite surfaces, showing unexpected potential fluctuations despite graphite's metallic nature.

Contribution

It demonstrates the coexistence of insulating and conducting behaviors on graphite surfaces using advanced microscopy techniques, revealing complex surface potential distributions.

Findings

Observation of micrometric potential domains on graphite surface.

Potential fluctuations of about 0.25V indicating mixed electronic behaviors.

Surface regions exhibit insulating behavior despite overall metallic conductivity.

Abstract

We present measurements of the electric potential fluctuations on the surface of highly oriented pyrolytic graphite using electrostatic force and atomic force microscopy. Micrometric domain-like potential distributions are observed even when the sample is grounded. Such potential distributions are unexpected given the good metallic conductivity of graphite because the surface should be an equipotential. Our results indicate the coexistence of regions with metallic and insulating behaviors showing large potential fluctuations of the order of 0.25V. We discuss the implications of these measurements in the disorder structure of graphite.