I thought that it was valid for very low temperatures since for it to be valid I think that it is necessary to be in the non-degeneracy condition, which requires $E_G >> k_B T$ (with $E_G$ being ...
Possible Duplicate: Impurity scattering temperature dependence Is there any temperature dependence of relaxation time in impurity scattering of conducting electrons? It seems to me that ...
What is Curie-Weiss temperature? What is the difference between Curie-Weiss temperature and Curie temperature?