How to interpret N(E) vs. E graphs when performing Auger spectroscopy

In summary: This is often referred to as the electron yield, intensity, or dI/dV. However, the exact definition may vary depending on the measurement conditions and setup. N(E) and N'(E) are usually plotted against the Auger electron energy, which is the kinetic energy of the emitted electrons.
  • #1
Ethan Mullen
5
0
TL;DR Summary
TL;DR : Can't figure out what N(E) vs. E graph means in AES
Hi all, my name's Ethan and I'm an undergraduate physics student conducting research on work functions this summer. I've been trying to understand the graphs of N(E) or N'(E) vs. auger electron energy for several days now, but I can't find in the literature what exactly N(E) or N'(E) are. I've seen N(E) referred to as electron yield, intensity, and even dI/dV, but nowhere have I seen a clear definition. I understand why N'(E) is often used instead of N(E), since the peaks where Auger electrons are emitted are often difficult to see on the N(E) graph, I just don't understand what either actually are. I've attached a picture below that shows an N'(E) vs. E graph for some more context. Thanks!
244673
 
Physics news on Phys.org
  • #2
Please see p.396 of this short pdf for further context. This is an example of a source that does not quite clarify what N(E) and N'(E) are.
 

Attachments

  • Auger reading 1.pdf
    460.5 KB · Views: 288
  • #4
Lord Jestocost said:
Maybe, this might be of help:
PDF]AES - Auger Electron Spectrosopy - Uni Ulm

Ah, thank you. I see that the author of this doc mentions that either the electron count or intensity is plotted vs. the kinetic energy. From what I've read about my particular setup, I will be using an electron multiplier to produce a greater number of electrons incident on the phosphor screen. I suppose, then, that the electron count itself isn't what's important. Rather, the relative change in the electron count is. Does this seem like a good assumption?
 
  • #5
Whether on prefers to measure N(E) or dN(E)/dE isn’t related to “importance”, but depends on the measurement conditions. The differential mode, dN(E)/dE, is preferred when there is a high background of secondary electrons, thus allowing a better assignment of the characteristic lines.
 
  • Like
Likes Ethan Mullen
  • #6
Lord Jestocost said:
Whether on prefers to measure N(E) or dN(E)/dE isn’t related to “importance”, but depends on the measurement conditions. The differential mode, dN(E)/dE, is preferred when there is a high background of secondary electrons, thus allowing a better assignment of the characteristic lines.
Thank you, but can you describe what N(E) actually is? I know that my system has a preamp hooked up to the apparatus, which means that my computer receives a digitized analog voltage, so how is the "current" actually being measured? I assume that N(E) is this mysterious "current" just translated to a voltage, but how is the current actually measured?
 
  • #7
The output signal is generally proportional to the count rate of electrons, dN(E)/dt: the number of electrons, dN(E), with a given energy, E, which are counted by the detector in a given time interval, dt.
 

1. What is N(E) vs. E graph in Auger spectroscopy?

N(E) vs. E graph is a plot of the number of electrons (N) detected at a specific energy (E) during Auger spectroscopy. It provides information about the energy distribution of electrons emitted during the Auger process.

2. How is N(E) vs. E graph interpreted in Auger spectroscopy?

The N(E) vs. E graph is interpreted by analyzing the peaks and shapes of the graph. The peaks correspond to the energies of the electrons emitted during the Auger process. The shape of the graph can also provide information about the electronic structure of the material being analyzed.

3. What is the significance of the energy scale in N(E) vs. E graph?

The energy scale in N(E) vs. E graph represents the kinetic energy of the electrons emitted during the Auger process. It allows for the identification of the elements present in the material being analyzed, as each element has a unique energy level at which its electrons are emitted.

4. How does the N(E) vs. E graph change for different materials?

The N(E) vs. E graph can vary for different materials depending on their electronic structure. The peak positions and shapes can be affected by factors such as the atomic composition, surface structure, and bonding of the material. Therefore, the graph must be interpreted carefully for each material.

5. Can the N(E) vs. E graph be used to determine the chemical composition of a material?

Yes, the N(E) vs. E graph can be used to determine the chemical composition of a material. By comparing the peak positions and shapes to known standards, the elements present in the material can be identified. However, other factors such as surface contamination must be taken into account for accurate results.

Similar threads

I How to understand experiment to measure heat capacity of solid?
    • Classical Physics
Replies
1
Views
593
I Assumptions for blackbody spectra vs. emission spectra vs. absorption spectra
    • Astronomy and Astrophysics
Replies
8
Views
2K
I Classical mass vs. relativistic mass for electronic analogy
    • Special and General Relativity
Replies
5
Views
1K
Questions about the Potential and E-Field directions of P-N junction
    • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
How exactly is information for CO transitions found?
    • Astronomy and Astrophysics
Replies
1
Views
1K
I Atmospheric Density vs Altitude in an O'Neil Cylinder
    • Classical Physics
Replies
1
Views
571
Admissions How to prove Physics competency to grad school admission committees?
    • STEM Academic Advising
Replies
24
Views
2K
How cross-section area of single E-M wave looks like?
    • Classical Physics
2
Replies
35
Views
9K
How is radio wave propagation modelled in seawater?
    • Optics
Replies
12
Views
9K
I Some questions about Cosmic Microwave Background radiation
    • Cosmology
Replies
13
Views
2K

Hot Threads

Recent Insights

Back
Top