Are there energy bands for alloys?

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In summary, the Fermi energy is a concept in metals that can be calculated using the electron concentration and energy at absolute zero. However, this calculation is more complex in alloys due to metallic bonding and crystalline structure. There are models and equations in quantum mechanics that can be used to determine the Fermi energy in alloys, but it requires further research and may not be as straightforward as in pure metals. The concept of Fermi surfaces is relevant in this context.
  • #1
Psinter
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In metals, there is a concept called the Fermi energy which you can calculate with the following:

Electron concentration in the solid:
[itex]
n = (valency)*\frac{N_{A}D}{M_{AT}}\\
[/itex]
Where:
[itex]n[/itex] = electron concentration
[itex]valency[/itex] = number of valency electrons in the atom
[itex]N_{A}[/itex] = Avogadro constant
[itex]D[/itex] = element density
[itex]M_{AT}[/itex] = atomic mass

Energy of Fermi at absolute zero (0K):
[itex]E_{F0} = (\frac{h^2}{2m_e})(\frac{3n}{\pi})^{\frac{2}{3}}(\frac{1}{q})[/itex]

Where:
[itex]E_{F0}[/itex] = energy of Fermi at absolute zero (0K)
[itex]h[/itex] = Plank's constant
[itex]m_e[/itex] = effective electron mass at rest
[itex]n[/itex] = electron concentration
[itex]\frac{1}{q}[/itex] = reciprocal of electron charge (to convert energy units to electron volts)

However, the math above is for a single element. Is there any quantum mechanical approach for the same concept, but in alloys where you have a metallic bonding and the same crystalline structure?

I want to know if there is such a thing as Fermi energy in such structures (alloys) that can be tackled mathematically in a quantum mechanical way. Such that one could describe conductivity properties of an alloy. Or if there are other models for that.
 
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  • #2
Yes, there is a Fermi level for alloys. It may not be so easy to calculate as in the simple model in your post.
Even for pure metals may be quite complicated actually.
 
  • #3
nasu said:
Yes, there is a Fermi level for alloys. It may not be so easy to calculate as in the simple model in your post.
Even for pure metals may be quite complicated actually.
Hi,

Thanks for your answer.

How much more complex does it get? Any hints of what is it I'm after? A set of Equations and principles in the Fermi-Dirac statistics perhaps?

I've been reading a book which discusses those quantum mechanical principles in metals. So far so good, but I haven't found what I'm looking for which is in the end, finding Fermi energy levels of an alloy. That book discusses what happens with Fermi Energies in a metal to metal contact, but not an alloy.

I've already covered a wide range of principles, including the Fermi-Dirac statistics and other models with their equations and examples for specific elements. Still, I can't find what I'm looking for. Therefore my question: any hints?
 
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nasu said:
You can look up some papers. Calculating the Fermi surface of a metal is not trivial, as I said. Usually is done by numerical methods, I suppose.
From the hits below you can see that the concept is used for alloys. If you want to do your own calculations you may need to read some books.

https://www.google.ca/webhp?sourcei...spv=2&ie=UTF-8#q=Fermi+surface+ordered+alloys
Thank you very much :smile:.

Later edit: Fermi surfaces is what I was looking for. Thanks again.
 
Last edited:
  • #6
You are welcome. Unfortunately I don't know details, I did not work in this field. I just have the general Solid State background.
 

Related to Are there energy bands for alloys?

1. What are energy bands in alloys?

Energy bands are a concept in solid state physics that refers to the distribution of energy levels available to electrons in a material. In alloys, which are mixtures of two or more metallic elements, the energy bands are affected by the different types of atoms present.

2. How do energy bands influence the properties of alloys?

The energy bands in alloys can affect various properties such as electrical conductivity, thermal conductivity, and magnetic properties. This is because the movement of electrons within the energy bands determines the behavior of the material.

3. Are energy bands the same for all types of alloys?

No, the energy bands in alloys can vary depending on the composition and structure of the alloy. Different types of alloys will have different energy band structures, leading to variations in their properties.

4. Can energy bands be manipulated in alloys?

Yes, energy bands in alloys can be manipulated through processes such as alloying, heat treatment, and doping. These methods can alter the composition and arrangement of atoms in the alloy, thus affecting the energy band structure.

5. Do energy bands in alloys play a role in the formation of defects?

Yes, the energy band structure of alloys can impact the formation of defects such as dislocations and vacancies. These defects can arise due to the interaction of electrons with the energy bands, leading to changes in the alloy's mechanical and chemical properties.

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