Stacking transition in rhombohedral graphite

TL;DR

This paper demonstrates controllable local transitions between ABC and ABA stacking in few-layer graphene using Joule heating and laser pulses, with high-resolution visualization of domain walls.

Contribution

It introduces two methods to controllably switch stacking order in FLG and visualizes the resulting domain walls at nanoscale resolution.

Findings

Joule heating induces controllable stacking transition.

Laser pulses can locally switch stacking order.

High-resolution imaging visualizes domain walls.

Abstract

Few layer graphene (FLG) has been recently intensively investigated for its variable electronic properties defined by a local atomic arrangement. While the most natural layers arrangement in FLG is ABA (Bernal) stacking, a metastable ABC (rhombohedral) stacking characterized by a relatively high energy barrier can also occur. When both stacking occur in the same FLG device this results in in-plane heterostructure with a domain wall (DW). We show that ABC stacking in FLG can be controllably and locally turned into ABA stacking by two following approaches. In the first approach, Joule heating was introduced and the transition was characterized by 2D-peak Raman spectra at a submicron spatial resolution. The observed transition was initiated at a small region and then the DW controllably shifted until the entire device became ABA stacked. In the second approach, the transition was achieved by illuminating the ABC region with a train of laser pulses of 790 nm wavelength, while the transition was visualized by transmission electron microscopy in both diffraction and dark field modes. Also, with this approach, a DW was visualized in the dark-field imaging mode, at a nanoscale spatial resolution.