Structural and electronic properties of grain boundaries in graphite: Planes of periodically distributed point defects

TL;DR

This study investigates the atomic-scale structure and electronic properties of grain boundaries in graphite, revealing periodic defect arrangements and localized electronic states through microscopy and spectroscopy.

Contribution

It introduces a geometrical model for periodic point defects at grain boundaries and provides detailed electronic characterization of these features.

Findings

Grain boundaries exhibit periodic structures and enhanced charge density.

Localized electronic states are observed at -0.3 V and 0.4 V.

Two possible periodic structures along grain boundaries are identified.

Abstract

We report on scanning tunneling microscopy and spectroscopy of grain boundaries in highly oriented pyrolytic graphite. Grain boundaries showed a periodic structure and an enhanced charge density compared to the bare graphite surface. Two possible periodic structures have been observed along grain boundaries. A geometrical model producing periodically distributed point defects on the basal plane of graphite has been proposed to explain the structure of grain boundaries. Scanning tunneling spectroscopy on grain boundaries revealed two strong localized states at -0.3 V and 0.4 V.