Now consider the quantum theory of conduction. At low temperatures, with scattering by lattice vibrations (phonons) not yet impo
rtant, ~ T. The residual resistivity, 0, as T -> 0 (the text calls this “I ”) is dependent on scattering by defects (impurities, . . .). If the lattice is ‘perfectly ordered’, then can approach infinity (or at least the size of the metal.) The residual resistivity is a measure of the purity of the sample. A relatively good sample of Cu has 0=2 10-11m.a.) If the Fermi velocity, uF, of Cu is 1.57 106 m/s, and =2 10-11m, according to eq. 10-25 what is the mean free path in units of m? (Assume Cu is monovalent, i. e. each atom contributes 1 electron to the conduction.) (show how the units come out to give units of length in the end.)
