The Specific Heat of a Free-Electron gas calculated by using the Fermi

In summary, the electron specific heat is hard to measure because it is a free energy term and the electron density is not given.
  • #1
nboogerz
4
0

Homework Statement



Here g(ε_f) is the density of levels at the Fermi energy and T is the temperature. Calculate the specific heat of the electron gas in potassium (K) treating it as a free gas. For a free gas the density of electrons at ε_f is: g(ε_f)=(3/2)(n/E_f) where n is the electron density in the gas. Why is the contribution of the electron specific heat so hard to measure?

Homework Equations



C_v=(1/3)(∏^2)(k_B)^2Tg(ε_f)

The Attempt at a Solution



Okay I'm taking n to be the total number of electrons in potassium(19) I still can't calculate a value for g(ε_f) as I still don't know what to put in for E_f as its not given in the problem. Also I'm not sure what to put in for T. Can I take this as another arbitary value as putting 0K for the temperature at the fermi level causes the equation to collapse.
 
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  • #2
nboogerz said:

Homework Statement



Here g(ε_f) is the density of levels at the Fermi energy and T is the temperature. Calculate the specific heat of the electron gas in potassium (K) treating it as a free gas. For a free gas the density of electrons at ε_f is: g(ε_f)=(3/2)(n/E_f) where n is the electron density in the gas. Why is the contribution of the electron specific heat so hard to measure?

Homework Equations



C_v=(1/3)(∏^2)(k_B)^2Tg(ε_f)

The Attempt at a Solution



Okay I'm taking n to be the total number of electrons in potassium(19) I still can't calculate a value for g(ε_f) as I still don't know what to put in for E_f as its not given in the problem. Also I'm not sure what to put in for T. Can I take this as another arbitary value as putting 0K for the temperature at the fermi level causes the equation to collapse.

It would be better if you consult from these sites:

http://www.cmmp.ucl.ac.uk/~ikr/3225/Section 6.pdf
http://www2.binghamton.edu/physics/docs/note-free-electron-gas.pdf
http://www.theo3.physik.uni-stuttgart.de/lehre/ss08/sst/Script-AHCN-Chap-6.pdf
http://phy.ntnu.edu.tw/~changmc/Teach/SS/SSG_note/mchap06.pdf
http://www2.binghamton.edu/physics/docs/note-free-electron-gas.pdf
 
  • #3


I'll have a look at them thanks.
 

What is the definition of specific heat?

Specific heat is the amount of heat energy required to raise the temperature of one gram of a substance by one degree Celsius.

How is the specific heat of a free-electron gas calculated?

The specific heat of a free-electron gas is calculated using the Fermi-Dirac distribution function, which takes into account the energy levels of free electrons in a system.

What is the importance of understanding the specific heat of a free-electron gas?

Understanding the specific heat of a free-electron gas is important in studying the thermal properties of materials, such as metals, which have a large number of free electrons. It also has applications in fields such as thermodynamics and solid state physics.

How does the specific heat of a free-electron gas differ from that of other substances?

The specific heat of a free-electron gas is typically much higher than that of other substances, as the energy levels of free electrons in a system are not restricted like those of atoms or molecules. This allows for more energy to be absorbed and released, resulting in a higher specific heat.

Can the specific heat of a free-electron gas be affected by external factors?

Yes, the specific heat of a free-electron gas can be influenced by external factors such as temperature, pressure, and the presence of impurities in the material. This can alter the energy levels of free electrons and therefore affect the overall specific heat of the system.

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