The failure of the free electron theory of metals

Click For Summary
SUMMARY

The free electron theory of metals, initially proposed by Drude and later modified by Sommerfeld, failed to accurately describe electron behavior in conductive materials such as silver. Key limitations include its inability to account for interactions with the lattice, electron-electron interactions, and impurities, which are crucial for understanding phenomena like magnetoresistance and thermal conductivity. Ashcroft and Mermin detail these failures in Chapter 3 of their book "Solid State Physics," emphasizing that the model was an approximation that surprisingly succeeded in some areas, such as the Wiedemann-Franz Law.

PREREQUISITES
  • Understanding of solid-state physics principles
  • Familiarity with the Drude and Sommerfeld models of electron behavior
  • Knowledge of Fermi statistics
  • Basic concepts of magnetoresistance and thermal conductivity
NEXT STEPS
  • Study the "nearly-free electron model" for advanced insights
  • Read Chapter 3 of "Solid State Physics" by Ashcroft and Mermin
  • Explore the implications of electron-electron interactions in metals
  • Investigate the Wiedemann-Franz Law and its applications
USEFUL FOR

Students and researchers in solid-state physics, materials scientists, and anyone interested in the limitations of classical models in explaining electron behavior in metals.

ziadett
Messages
8
Reaction score
0
I was woundering?

why did the free electron theory of metals fail (the free electron model)?
 
Last edited:
Physics news on Phys.org
why did the free electron theory of metals fail "the free electron of model"
my effort:
Because it was unable to answer why the mean free path of electrons reaches 20nm in a good conducting metal "like silver" in room tempereture.
 
Last edited:
any answers
 
Who said it failed?
 
nbo10 said:
Who said it failed?

Ashcroft and Mermin did in the whole of Chapter 3 of their book "Solid State Physics".

Zz.
 
ziadett said:
why did the free electron theory of metals fail (the free electron model)?
The free electron model (as put forth by Drude, and modified by Sommerfeld and others) "failed" because for the most part, electrons aren't completely free. They interact with (i) the lattice, (ii) each other, and (iii) impurities. Drude incorporated (i) into his model in the form of a hard-sphere interaction, but completely neglected the other interactions. Sommerfeld made some corrections to this purely classical model, by ensuring that the electron gas obey Fermi statistics. This fixed some problems (like the overestimates of the electronic heat capacity), but still didn't cover for the missing interactions in the model.

The free electron model was understood to be an approximation, when it was proposed by Drude. The initial surprise was that it was far more successful than expected (eg: the Wiedemann-Franz Law), particularly in the case of the alkali and alkaline Earth elements.

Due to its limitations, the free electron model was unable to account for things like magnetoresistance, thermal dependence of conductivity, optical properties and the host of many body phenomena that result from electron-electron interactions being of importance.
 
Aren't the "free-electron theory" and the "free-electron model" the same thing?

You might try looking up the "nearly-free- electron model."
 
Look up chapter three in Ashcroft&Mermin, it just happens to be named "Failures of the Free Electron Model" and probably contains more than enough information for you.
 
  • #10
Thread merged.

ziadett : I strongly suggest you re-read the PF Guidelines that you have agreed to. There is a an explicit instruction that multiple posting is not allowed.

Zz.
 
  • #11
sorry man no more multiple posting from me any more
 

Similar threads

Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
3
Views
2K
Replies
3
Views
2K
  • · Replies 28 ·
Replies
28
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 12 ·
Replies
12
Views
2K
Replies
1
Views
2K