Location of electrons (not excess charge) in a conductor [static case]

In summary: Fig. 4: The Friedel oscillations. The electron density near the surface oscillates between two levels, the so-called Friedel levels. The oscillations are damped by the Coulomb interaction between the electrons and the nuclei.
  • #1
Kostik
75
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In a conductor, excess charge resides on the surface. That seems odd, because one would think that the overall energy of the system could be lowered by allowing some of the excess charge to move inward and away from all the charge on the surface, but obviously that can't be true, because charge inside the conductor would create a field that causes other charges to move. (I suppose a single excess point charge could disengage from the surface and take up residence inside the conductor, but only one!)

My question concerns the free electrons that belong to the atoms in the conducting material. Suppose there is no excess charge in the conductor: just a solid block of copper. Are the free electrons distributed uniformly throughout the material? Every copper atom looks neutral to an electron located far away from it, so I suppose there are no forces present that would act on the free electrons, other than the coloumb force of the nucleus to which it is nominally attached.
 
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  • #2
Hi.
Kostik said:
Summary:: Suppose there is no excess charge in a conductor, i.e., consider a solid block of copper. Are the free electrons distributed uniformly throughout the material?

In bulk yes but on surface band structure changes and it would cause surface states of free electrons in general.

ref. WIKI surface states https://en.wikipedia.org/wiki/Surface_states
 
  • #3
Kostik said:
Summary:: Suppose there is no excess charge in a conductor, i.e., consider a solid block of copper. Are the free electrons distributed uniformly throughout the material?
Theories of metal surfaces have to consider the rapid decrease of the electron density near the surface and the loss of translational symmetry. In the framework of the jellium model of metal surfaces, the electron distribution does not follow the sharp edge of the positive background but rather exhibits a damped oscillatory structure inside the jellium, the so-called Friedel oscillations. Have a look at Fig. 4 in the paper "Theory of Metal Surfaces: Charge Density and Surface Energy" by N. D. Lang and W. Kohn, Phys. Rev. B 1, 4555, 1970:

Theory of Metal Surfaces: Charge Density and Surface Energy
 

1. Where are the electrons located in a conductor?

The electrons in a conductor are located in the outermost energy level of the atoms that make up the material. They are also constantly moving and interacting with each other.

2. How are the electrons distributed in a conductor?

The electrons in a conductor are evenly distributed throughout the material. This allows for efficient flow of electricity through the material.

3. Do the electrons in a conductor have a specific path or trajectory?

No, the electrons in a conductor do not have a specific path or trajectory. They move randomly and rapidly due to thermal energy and interactions with other particles.

4. Can the location of electrons in a conductor change?

Yes, the location of electrons in a conductor can change. This can happen through the application of an external electric field or through interactions with other particles in the material.

5. How does the location of electrons in a conductor affect its conductivity?

The location of electrons in a conductor plays a crucial role in its conductivity. The more freely and evenly the electrons can move, the higher the conductivity of the material will be.

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