Week 10 Electronic Transport in Metals Flashcards
what 3 assumptions does the Drude model make
> electrons are scattered by ionic core only
no interactions between collisions
electrons achieve thermal equilibrium with surroundings only through collision
what is the Drude force equation
F = -eE = mv/τc
what is the mobility equation in terms of collision time
μ = eτc/m
what is the conductivity equation in terms of collision time
σ = neτc/m
what is the resistivity equation in terms of collision time
ρ = 1/σ = m/neτc
what is the flux equation in terms of thermal conductivity
F = κdT/dx
what is the Wiedemann-Franz law equation
κ/σ = LT
where is the Lorenz number
what happens when an electric field is applied to a fermi sphere
the sphere is shifted due to electrons acquiring drift velocity however this effect is very small
what are the two reasons for electrons scattering in the Fermi sphere
lattice vibrations (phonons) imperfections and impurities
what is the total collision time equation
1/τc = 1/τi + 1/τp
what is the total resistivity equation
ρ = ρ0 + ρ(T)
what is true of the two different collision times
phonon collision time is temperature dependent whereas the imperfections collision time is not
