Fermi velocity electron resistivity

The observed first power relation between resistivity and temperature implies that the collision velocity must not only be independent of the applied field and be much greater than the drift velocity but must also be independent of temperature, which rules out the thermal velocity as the motion responsible for the observed collision rate. With the discovery of quantum mechanics, the difficulties encountered by the classical electron gas model are resolved by having the electrons travel at the Fermi velocity. 

The electrical resistivity of gold, at 273 K, is 2.05 X 10 0 m. Gold adopts the A1 structure with a cubic lattice parameter, oq, of 0.4078 nm. The velocity of electrons at the Fermi surface is 1.40 x 10 ms. Each gold atom contributes one electron to the structure. Calculate the relaxation time, t,... 

The electrical resistivity of liquid mercury as a function of temperature is given in Table 13.3. The velocity of electrons at the Fermi... 

---