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An Introduction to Auger Electron Spectroscopy

Ha Nguyen

CHM 1046H

Application

* Auger Depth Profiling=>depth below the surface.

* Identification of Microscopic.

* Scanning Auger Microscopy.

* Corrosion and oxidation.

*Quantitation of light element surface film.

* Determine sex and age based on the ratio of Ca/P of different bone sites.

The Auger process

The electron detector

The schematic of an arrangement

The electron energy analyzer

Detector communicates with energy respect to time data.

- The primary electron from electron gun collides with 1s-shell electron .

- The secondary e- gets excited and dispersed.

- Electron from 2s-shell fills the vacancy and emits Auger electron.

Its function is to disperse the secondary electron and transfer it to electron detector.

- UHV environment - Electron gun

- Electron analysis - Electron detector

- Data acquisition

The data is analyzed to find out the data peak

The de-excitation of electron

- If the source atom has been closer to the surface, then a greater fraction of the emitted electrons would have been detected.

* Peaks in the spectrum identify the elemental composition of the sample surface.

Conclusion

Auger Electron Spectroscopy is the best instrument to study spatial resolution, light element, and surface depth by determining the identification physical and chemical characteristics of the surface sample.

The energy detected by an expression

Eke=EK - 2EL - ϕ

References:

Eke: the kinetic energy

EK: kinetic energy of electron in the K shell

EL: kinetic energy of electron in the L shell

ϕ: work function of the detector

Introduction

- Gaurv, Nair. Mithun, P. Naveen, S. Nipin, L. “Auger Electron Spectroscopy”. Web. March 22, 2016.

http://www.mecheng.iisc.ernet.in/~bobji/mspc/assign/AES.htm

- University At Albany. “Auger Electron Spectroscopy (AES). Elementals and Appilcation”. Web. March 26th, 2016.

http://chemistry.st-and.ac.uk/staff/gh/teaching/CH5711/Further%20reading/auger.pdf

  • Determining and analyzing the outermost chemical surface composition.

  • By determining kinetic energy of Auger electron => atom is defined.

* Plot of spectrum is the back scattered electrons versus kinetic energy per unit energy interval .

History

Auger Electron Spectroscopy

Lise Meitner

  • An Austrian physics (1878-1968).
  • Discover this effect independently in 1923.
  • Her contribution was reported in the journal Zeitschrift für Physik.

Pierre Auger

  • A French physics (1899-1993), was credited in the most scientific community in 1925.
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