Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

189 submissions , 149 unreviewed
4,784 questions , 1,976 unanswered
5,282 answers , 22,468 comments
1,470 users with positive rep
772 active unimported users
More ...

  How much Curie temperature $T_C$ is obtained according to the Stoner model?

+ 0 like - 0 dislike
53 views

In Stoner model for itinarant ferromagnetism, the spin ordering of electrons is caused by the Coulomb interaction UU for onsite repulsion leading to the reduction of total energy against to the enhanced kinetic energy. If one can induce an imbalence $δn$ between total amount of spin-up and spin-down electrons, the kinetic energy $E_k$ will increase with $δE_k=\frac{1}{D_F}(δn)^2$ while the Coulomb repulsion energy will change with $δE_C=−U(δn)^2$. Therefore, we can normally obtain the Stoner criterion for itinerant Ferromagnetism:

$$δE=δE_k+δE_C=\frac{1}{D_F}(δn)^2(1−D_F U)$$

in which the $D_FU>1$ corresponds to the ferromagnetism, while $D_FU<1$ corresponds to the paramagnetism.

I survey in many textbooks and note on interent, however, most of documents only domenstate above criterion, the value of estimated Curie temperature is remained elusive for me.

In particular, above consideration is not fully addressed all my confusions. If an imbalence δnδn is intruduced by some perturbation, the total energy decreases without any limitation, and finally all spin will be aligned and extremely robust against thermal fluctuation, which will thus will result to an inceadiblely high Curie temperature.

So, how much Curie tempeature should be in Stoner model ?

asked Aug 19 in Q&A by qfzklm (20 points) [ no revision ]

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
$\varnothing\hbar$ysicsOverflow
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
To avoid this verification in future, please log in or register.




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...