Imaging of isotope diffusion using atomic-scale vibrational spectroscopy
arXiv:2306.15861 · doi:10.1038/s41586-022-04405-w
Abstract
The spatial resolutions of even the most sensitive isotope analysis techniques based on light or ion probes are limited to a few hundred nanometres. Although vibration spectroscopy using electron probes has achieved higher spatial resolution, the detection of isotopes at the atomic level has been challenging so far. Here we show the unambiguous isotopic imaging of 12C carbon atoms embedded in 13C graphene and the monitoring of their self-diffusion via atomic level vibrational spectroscopy. We first grow a domain of 12C carbon atoms in a preexisting crack of 13C graphene, which is then annealed at 600C for several hours. Using scanning transmission electron microscopy electron energy loss spectroscopy, we obtain an isotope map that confirms the segregation of 12C atoms that diffused rapidly. The map also indicates that the graphene layer becomes isotopically homogeneous over 100 nanometre regions after 2 hours. Our results demonstrate the high mobility of carbon atoms during growth and annealing via selfdiffusion. This imaging technique can provide a fundamental methodology for nanoisotope engineering and monitoring, which will aid in the creation of isotope labels and tracing at the nanoscale.
References in corpus (7)
- Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
- Evolution of graphene growth on Cu and Ni studied by carbon isotope labeling
- Graphene re-knits its holes
- Position and momentum mapping of vibrations in graphene nanostructures in the electron microscope
- Vibrational Spectroscopy at Atomic Resolution with Electron Impact Scattering
- Isotope analysis in the transmission electron microscope
- Atomic-Scale Vibrational Mapping and Isotope Identification with Electron Beams