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

AI Thread Summary
The discussion focuses on calculating the specific heat of a free-electron gas in potassium using the Fermi energy. The equation for specific heat, C_v, involves the density of states at the Fermi energy, g(ε_f), which is challenging to determine without knowing the Fermi energy, E_f, or the temperature, T. Participants express difficulty in calculating g(ε_f) due to missing values for E_f and the appropriate temperature, questioning whether T can be arbitrarily chosen. The complexity of measuring the electron-specific heat is also highlighted, suggesting inherent challenges in experimental setups. Resources are recommended for further understanding of the topic.
nboogerz
Messages
4
Reaction score
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.
 
Physics news on Phys.org
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
 


I'll have a look at them thanks.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top