Single-atom vibrational spectroscopy with chemical-bonding sensitivity.
Mingquan XuDe-Liang BaoAowen LiMeng GaoDongqian MengAng LiShi-Xuan DuGang SuStephen John PennycookSokrates T PantelidesWu ZhouPublished in: Nature materials (2023)
Correlation of lattice vibrational properties with local atomic configurations in materials is essential for elucidating functionalities that involve phonon transport in solids. Recent developments in vibrational spectroscopy in a scanning transmission electron microscope have enabled direct measurements of local phonon modes at defects and interfaces by combining high spatial and energy resolution. However, pushing the ultimate limit of vibrational spectroscopy in a scanning transmission electron microscope to reveal the impact of chemical bonding on local phonon modes requires extreme sensitivity of the experiment at the chemical-bond level. Here we demonstrate that, with improved instrument stability and sensitivity, the specific vibrational signals of the same substitutional impurity and the neighbouring carbon atoms in monolayer graphene with different chemical-bonding configurations are clearly resolved, complementary with density functional theory calculations. The present work opens the door to the direct observation of local phonon modes with chemical-bonding sensitivity, and provides more insights into the defect-induced physics in graphene.
Keyphrases
- density functional theory
- molecular dynamics
- high resolution
- molecular dynamics simulations
- single molecule
- electron microscopy
- energy transfer
- gene expression
- high glucose
- endothelial cells
- climate change
- genome wide
- raman spectroscopy
- single cell
- patient reported outcomes
- quantum dots
- electron transfer
- stress induced