Electrical & thermal conductivities

In summary, the correlation between electrical and thermal conductivities in metals is based on the fact that both involve the free movement of electrons. The Wiedemann-Franz law is an empirical fact that shows the relationship between these variables, but does not explain the underlying mechanism. While there are more complex models for transport, the presence of free electrons is ultimately the key factor in this correlation.
  • #1
bentzy
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What's the mechanism underlying the correlation between electrical & thermal conductivities in metals ?
What's the mechanism underlying the correlation between electrical & thermal conductivities in metals ?
 
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Wiedemann-Franz law is not the mechanism, but, rather, an empirical fact. An empirical law doesn't explain a phenomenon on its basic mechanism/s, but just gives the relation between variables. In other words, it is the result of, not its cause.
 
  • #4
The relationship is based upon the fact that heat and electrical transport both involve the free electrons in the metal.
 
  • #5
Right. Both are based on the motion of (nearly) free electrons (mostly). This is of course known. My question aims at the deeper level of the mechanism itself, which make up the overall picture of transport.
 
  • #6
The fact that the electrons are free to move IS the mechanism in this case(!)
Of course you can use more realistic (and complicated) models for the transport; but ultimately the correlation is due to the presence of free electrons; it is not more complicated than that.
 
  • #7
bentzy said:
An empirical law doesn't explain a phenomenon on its basic mechanism/s, but just gives the relation between variables.
Good thing Wikipedia has that "Derivation" tab to let you know where the law comes from.
 

FAQ: Electrical & thermal conductivities

What is electrical conductivity?

Electrical conductivity is the measure of a material's ability to conduct an electric current. It is typically measured in siemens per meter (S/m) or mho per meter (mho/m), with higher values indicating better conductivity.

How is electrical conductivity different from thermal conductivity?

Electrical conductivity refers to a material's ability to conduct electricity, while thermal conductivity refers to its ability to conduct heat. While both involve the transfer of energy, they are separate properties and are measured in different units.

What factors affect electrical and thermal conductivities?

Electrical and thermal conductivities are affected by a variety of factors, including the material's composition, temperature, and the presence of impurities or defects. In general, materials with high electrical conductivity also have high thermal conductivity.

How do electrical and thermal conductivities impact everyday life?

Electrical and thermal conductivities play a crucial role in many aspects of everyday life, from powering our devices and homes to regulating the temperature of our food and drinks. They also have important applications in industries such as electronics, transportation, and construction.

Can electrical and thermal conductivities be changed or improved?

Yes, electrical and thermal conductivities can be altered through various methods such as doping, alloying, and heat treatment. These techniques can be used to improve the performance of materials in specific applications or to create new materials with desired properties.

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