The resistivity of pure copper is increased by about 1 ? 10 -8 ? ? m by

Question:

The resistivity of pure copper is increased by about 1 ? 10^-8 ? ? m by the addition of 1% (by number of atoms) of an impurity throughout the metal. The mean free path depends on both the impurity and the oscillations of the lattice ions according to the equation

(a) Estimate ?i from data given in Table 27-1.

(b) If r is the effective radius of an impurity lattice ion seen by an electron, the scattering cross section is ?r2. Estimate this area using the fact that r is related to ?i by Equation 27-9.