Ultrafast core-loss spectroscopy in four-dimensional electron microscopy.
Struct Dyn
; 2(2): 024302, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-26798793
ABSTRACT
We demonstrate ultrafast core-electron energy-loss spectroscopy in four-dimensional electron microscopy as an element-specific probe of nanoscale dynamics. We apply it to the study of photoexcited graphite with femtosecond and nanosecond resolutions. The transient core-loss spectra, in combination with ab initio molecular dynamics simulations, reveal the elongation of the carbon-carbon bonds, even though the overall behavior is a contraction of the crystal lattice. A prompt energy-gap shrinkage is observed on the picosecond time scale, which is caused by local bond length elongation and the direct renormalization of band energies due to temperature-dependent electron-phonon interactions.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Struct Dyn
Ano de publicação:
2015
Tipo de documento:
Article