EELS analysis of carbon structures

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EELS analysis of carbon structures
Gergely Kovách MTA MFA

• Nanotube seminar
• 2005. 05. 09.

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Electron spectroscopy

• EELS, electron energy loss is characteristical to
  the material
• XPS, binding energy of C1s (284.6eV, 285.4eV)
  core level electron, energy loss of core level
  electron

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Electron energy loss in solids
a zero loss b fonons c band transitions
d surface plasmons e bulk plasmons f inner
shell absorption edge
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Hybridization of C atoms

• Energy difference in hybridized orbitals
• Broadening of ? bonds
• Also valid for amorphous structure

-Pre edge feature in C1s-2p absorption 1s-2p(?)
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Core level absorption spectra of C samples
DLC Graphite Evap. C
STEM at 100 kV
J. Yuan, Micron 515 (2000)
sp2/sp3 obtained from peak intensity
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Polarization of 1s-2pz transition
Anisotropic response of 1s-2p dipole transition
-gt difficulties in quantitative analysis
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sp2/sp3 ratioPlasmon energy shift
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sp2/sp3 ratiousing reference material
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sp2/sp3 ratioC1s binding energy
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Own measurements
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References

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