nl9b00654_si_001.pdf (1.62 MB)
Probing Exfoliated Graphene Layers and Their Lithiation with Microfocused X‑rays
journal contribution
posted on 2019-05-16, 00:00 authored by Patrik Zielinski, Matthias Kühne, Daniel Kärcher, Federico Paolucci, Peter Wochner, Sven Fecher, Jakub Drnec, Roberto Felici, Jurgen H. SmetX-ray
diffraction is measured on individual bilayer and multilayer
graphene single-crystals and combined with electrochemically induced
lithium intercalation. In-plane Bragg peaks are observed by grazing
incidence diffraction. Focusing the incident beam down to an area
of about 10 μm × 10 μm, individual flakes are probed
by specular X-ray reflectivity. By deploying a recursive Parratt algorithm
to model the experimental data, we gain access to characteristic crystallographic
parameters of the samples. Notably, it is possible to directly extract
the bi/multilayer graphene c-axis lattice parameter.
The latter is found to increase upon lithiation, which we control
using an on-chip peripheral electrochemical cell layout. These experiments
demonstrate the feasibility of in situ X-ray diffraction on individual,
micron-sized single crystallites of few- and bilayer two-dimensional
materials.